Zahid Hussain was the first Governor of the State Bank of Pakistan when it was established in 1948. The State Bank serves as the central bank of the country and is responsible for monetary policy, currency issuance, and financial stability. As the first governor, Zahid Hussain played a crucial role in setting up the banking system of the newly independent Pakistan. His leadership helped establish financial institutions and regulatory frameworks. Other options include later officials or unrelated figures. Shamshad Akhtar served much later, while Malik Ghulam Muhammad was a political figure. Thus, Zahid Hussain is the correct answer, marking an important milestone in Pakistan’s economic history.

The Paris Climate Conference (COP21) was held in 2015, leading to the Paris Agreement aimed at limiting global warming below 2°C.

Pepsinogen is an inactive precursor, or zymogen, secreted by the gastric glands in the stomach lining. It is converted into its active form, pepsin, in the presence of hydrochloric acid (HCl). This acidic environment triggers the activation process. Pepsin is a proteolytic enzyme that begins the digestion of proteins by breaking them down into smaller peptides. This process is essential for further digestion and absorption in the small intestine. The conversion of pepsinogen into pepsin is a protective mechanism. If pepsin were active inside the cells that produce it, it could digest the stomach lining itself. By secreting it in an inactive form, the body prevents self-damage. Other options are incorrect: “enzyme” is too general, proteins are the substrate, and amylase digests carbohydrates. Thus, pepsin is the correct answer. This concept is important for understanding enzyme activation and digestive physiology, commonly tested in exams.

A simple data structure refers to a basic and linear way of organizing data in memory. Among the given options, an array is considered the simplest data structure. It stores elements of the same type in contiguous memory locations, allowing direct access using an index. This makes arrays efficient for accessing and storing data when the size is known in advance. Arrays are widely used in programming because of their simplicity and speed. They allow constant time access (O(1)) to elements, which is a major advantage over more complex structures. However, arrays have limitations such as fixed size and difficulty in insertion or deletion operations. Graphs, trees, and networks are non-linear and more complex data structures. They are used for advanced applications like hierarchical data representation and relationships. Thus, array is the correct answer because it represents the most basic and fundamental data structure in computer science.

Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are primarily composed of proteins, which are made up of amino acids folded into specific three-dimensional structures. This structure is crucial because it determines the enzyme’s active site, where substrates bind and reactions occur. Enzymes are highly specific, meaning each enzyme typically catalyzes a particular reaction. Vitamins and minerals may act as cofactors or coenzymes, assisting enzyme function, but they are not the main structural components. Carbohydrates do not form enzymes. Thus, proteins are the correct answer. This concept is fundamental in biochemistry and helps explain how metabolic processes occur efficiently in living organisms.