Step 1: Understanding the context.
The first estimation of national income in India was attempted by Dadabhai Naoroji, a renowned Indian nationalist and economist.
Step 2: Historical fact.
In 1868, Dadabhai Naoroji estimated the national income and highlighted how wealth was draining from India to Britain (Drain of Wealth theory).
Step 3: Analyzing the options.
(A) 1798: No record of national income calculation.
(B) 1848: Not the correct year.
(C) 1868: Correct — Dadabhai Naoroji’s estimation.
(D) 1911: Later studies were done but not the first.
Step 4: Conclusion.
Thus, the first estimation of India’s national income was done in 1868.