Step 1: Analyse the clues.
The person mentioned was a physician, conducted surveys in Bengal, and later adopted the surname Hamilton. These are strong historical identifiers.
Step 2: Identify Francis Buchanan.
Francis Buchanan was a Scottish physician who worked in India under the British East India Company. He carried out extensive surveys in Bengal and other regions.
Step 3: Name change and contributions.
He later adopted the name Buchanan-Hamilton after inheriting property. He is also known for his contributions to zoology and is associated with early efforts related to zoological collections in Calcutta.
Step 4: Eliminate other options.
Col. Mackenzie was a surveyor but not a physician.
Thomas Munroe was an administrator.
Charles Mountbatten was a later British figure (20th century).
Step 5: Conclusion.
Thus, the correct answer is Francis Buchanan.
Final Answer: Francis Buchanan
Two statements are given below as Assertion and Reason (R). Read them carefully and choose the correct option.
Assertion : Harappa was a well-planned city.
Reason (R): It had a well-planned drainage system.
Match Column-I with Column-II and choose the correct option: 
Identify the ancient Indian text with the help of the following information: