Step 1: Understanding the Question:
• The question asks who is considered the father of public health.
Step 2: Detailed Explanation:
• The official NTA final answer key accepts John Snow (option A). John Snow is known for tracing the 1854 London cholera outbreak to the Broad Street pump, a landmark in public health.
• The other names (Chadwick, John Simon, William Budd) are also associated with sanitary reform or disease causation, but the key marks John Snow as the answer.
Step 3: Final Answer:
The correct option is (A) John Snow.