Consider the following statements about Indian Economic History and find the 'correct statements'.
1. Dadabhai Naoroji explained drain theory in his book 'Poverty and Un-British rule in India'.
2. Romesh Chandra Dutt examined in minute detail the entire economic record of colonial rule since 1857 in his book 'The Economic History of India'.
1. 1 only
2. 2 only
3. Both 1 and 2
4. Neither 1 nor 2