Step 1: Understanding the Context:
After independence, India adopted a model of economic development based on Five-Year Plans, formulated by the Planning Commission. The question asks to identify the key intellectual figure behind the initial plans.
Step 2: Detailed Explanation:
Prasanta Chandra Mahalanobis was a renowned Indian statistician and physicist. He was a member of the Planning Commission of India from its inception in 1950 until his death in 1972.
His most significant contribution was the Mahalanobis model, which was the mathematical framework for the Second Five-Year Plan (1956-61). This model emphasized rapid industrialization with a focus on developing a strong heavy industry and public sector. Due to this foundational role in shaping India's economic strategy, he is widely regarded as the 'Architect of Indian Planning'.
The other individuals listed, while they may be economists or academics, are not associated with this title or the foundational role in the same way as Mahalanobis.
Step 3: Final Answer:
Prasanta Chandra Mahalanobis is known as the Architect of Indian Planning.