Explanation:

- Alexander Cunningham is the correct answer. He was the first Director-General of the Archaeological Survey of India (ASI). Appointed in 1861, he is often referred to as the "father of Indian archaeology" due to his pioneering work in systematically documenting India's vast array of historical and archaeological sites.

- Mortimer Wheeler (Option 1) was a British archaeologist who later served as Director-General of ASI from 1944 to 1948. He was known for introducing modern archaeological techniques in India.

- Lord Curzon (Option 3) was not a Director-General but the Viceroy of India from 1899 to 1905. He played a significant role in promoting the preservation of Indian monuments.

- John Marshall (Option 4) was appointed Director-General in 1902 and served until 1928. He is credited with extensive archaeological work, including the discovery of the Indus Valley Civilization.

Thus, Option 2: Alexander Cunningham is the correct and relevant choice.