Kirthar range spans Sindh and Balochistan, so both A & B correct.

Edward Jenner, an English physician, is credited with developing the first successful vaccine in 1796. He discovered that milkmaids who had contracted cowpox were immune to smallpox, a deadly disease at the time. Jenner tested his theory by inoculating a young boy with material from cowpox lesions and later exposing him to smallpox. The boy did not develop the disease, proving immunity. This discovery laid the foundation for immunology and modern vaccination. It led to the eventual eradication of smallpox worldwide. Other options are incorrect as they do not match the historical timeline. Thus, 1796 is the correct answer, marking a major breakthrough in medical science and public health.

This UN day is observed on 17 June to raise awareness about desertification and drought issues worldwide.

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.

Smooth ER synthesizes lipids such as phospholipids and steroids. It also helps in detoxification. Protein synthesis occurs in rough ER, not smooth ER.