A parsec is a unit of distance used in astronomy. It is defined as the distance at which one astronomical unit subtends an angle of one arcsecond. One parsec is approximately equal to 3.26 light-years. It is commonly used to measure distances between stars and galaxies because these distances are extremely large. Speed, time, and acceleration are different physical quantities and do not apply here. Therefore, distance is the correct answer. Parsec is especially useful in parallax measurements, where astronomers calculate distances based on the apparent shift of a star’s position.

The Batura Glacier is located in Gilgit-Baltistan, Pakistan, within the Karakoram mountain range. It is one of the longest glaciers outside the polar regions, stretching approximately 57 kilometers. This glacier is significant because it contributes to the Hunza River, which is part of the Indus River system—Pakistan’s main water source. Glaciers like Batura are crucial for maintaining water supply for agriculture, hydropower, and daily use. Unlike many glaciers worldwide that are retreating due to climate change, some glaciers in the Karakoram region, including Batura, have shown relative stability or even slight growth, a phenomenon known as the “Karakoram anomaly.” Although the Karakoram range extends into China, the Batura Glacier lies within Pakistani territory. Afghanistan and Tibet do not contain this glacier. Thus, Pakistan is the correct answer. Understanding glacier locations is important for geography, environmental science, and water resource management.

Mars has two natural satellites, Phobos and Deimos. These moons were discovered in 1877 by astronomer Asaph Hall. They are small, irregularly shaped bodies, believed to be captured asteroids or formed from debris. Phobos is the larger moon and orbits very close to Mars, completing a revolution in about 7 hours. Deimos is smaller and orbits farther away, taking about 30 hours. Unlike Earth, which has one moon, and Mercury and Venus, which have none, Mars has two moons. This makes option B correct. These moons are of great scientific interest because they provide clues about the formation and evolution of the solar system. Future missions may explore them further. Thus, the correct answer is 2.

Benjamin Franklin, a prominent American scientist and statesman, invented both the lightning rod and bifocal spectacles. His lightning rod invention emerged from his experiments with electricity, including the famous kite experiment, which demonstrated that lightning is a form of electrical discharge. The lightning rod protects buildings by directing electrical energy safely into the ground, preventing fires and structural damage. This invention had immediate practical importance and is still widely used today. Franklin also invented bifocal spectacles to address his own vision problems. These glasses combine two lenses in one frame, allowing a person to see both near and distant objects clearly without switching glasses. This was a major convenience and innovation in optics. Other options are notable scientists but unrelated to both inventions: Thomas Edison developed electric devices, Alessandro Volta invented the battery, and Benjamin Banneker was a mathematician and astronomer. Therefore, Benjamin Franklin is the correct answer, as he contributed significantly to both electrical science and practical inventions improving daily life.

Sunspots are dark regions that appear on the surface of the Sun due to intense magnetic activity that lowers the surface temperature in those areas. The first recorded telescopic observation of sunspots is credited to Thomas Harriot, an English astronomer, in 1610. He used an early telescope to observe the Sun and documented these spots before Galileo’s more widely known observations. This discovery challenged the long-standing Aristotelian belief that celestial bodies were perfect and unchanging. The presence of spots on the Sun suggested that it was dynamic and imperfect. Later astronomers such as Galileo Galilei and Christoph Scheiner studied sunspots more extensively and tracked their movement, which helped establish that the Sun rotates on its axis. Albert Einstein is known for the theory of relativity, Isaac Newton for gravity and laws of motion, and René Descartes for contributions to philosophy and mathematics. None of them observed sunspots first. Thus, Thomas Harriot is considered the earliest observer, making option D correct. His work contributed significantly to the development of modern astronomy and our understanding of solar activity.