Step 1: Understanding the Planning Commission.
The Planning Commission of India was responsible for formulating Five-Year Plans and guiding India’s economic and social development in the post-independence period.
Step 2: Historical background.
Although the Planning Commission was constituted in 1950, it became fully functional with the launch and implementation phase of planned economic development through the First Five-Year Plan, which came into operation in the early 1950s.
Step 3: Analyzing the options.
(A) 1948: Incorrect, as the Planning Commission did not exist at that time.
(B) 2015: Incorrect, as this year marks the replacement of the Planning Commission by NITI Aayog.
(C) 1994: Incorrect, as the Planning Commission was active much earlier.
(D) 1952: Correct — this period is associated with the operational launch of planned development through Five-Year Plans.
Step 4: Conclusion.
The correct answer is (D) 1952.