Explanation:

- The Estimates Committee was first constituted in India to examine the budget estimates proposed by the Government of India.

- It plays a crucial role in ensuring accountability and effective utilization of public funds.

- Let's evaluate the provided options:

- Option 1: 1948 - This is incorrect. The committee was not constituted in this year.

- Option 2: 1950 - This is incorrect. While significant changes occurred in 1950, the Estimates Committee began earlier.

- Option 3: 1947 - This is incorrect. India gained independence in this year, but the committee was not set up yet.

- Option 4: 1949 - This is correct. The Constitution of India, implemented in 1950, was preceded by the formation of several committees, including the Estimates Committee in 1949.