The correct answer is 4 because 2+2=4.

DNA, or Deoxyribonucleic Acid, carries genetic instructions in living organisms, forming the blueprint of biological development.

Robert Hooke used a microscope in 1665 to describe cork structures as “cells,” laying the foundation for modern cell biology.

The Black Death (1347–51) killed about one-third of Europe’s population, spread by fleas on rats. This is a well-documented historical or scientific.

Sputnik 1, launched by the USSR in 1957, was the first artificial satellite, marking the start of the space race.

The 1054 Schism split Christianity into Roman Catholicism (West) and Eastern Orthodoxy (East). This is a well-documented historical or scientific.

Nicolaus Copernicus proposed the heliocentric model in 1543, stating Earth revolves around the Sun, challenging geocentric beliefs.

The Gupta Empire (4th–6th century CE) in India saw great achievements in science, art, literature, and mathematics.

Due to overseas territories, France spans the most time zones of any country when its territories are included across the globe.

Mitochondria generate energy in the form of ATP through cellular respiration, hence called the cell’s powerhouse.