Assertion: The planning process has to take special care of those areas which have remained economically backward.
Reasoning: In order to arrest the accentuation of regional and social disparities, the Planning Commission introduced the ‘target area’ and target group approaches to planning.

Both Assertion (A) and reasoning (R) are correct, and R is the correct explanation of A.

The correct answer is Option 1: Both Assertion (A) and reasoning (R) are correct, and R is the correct explanation of A.

Assertion: The planning process has to take special care of those areas which have remained economically backward. This is correct. This is a fundamental principle of balanced regional development. In a diverse economy, leaving specific regions behind creates a "vicious cycle of poverty" that can hamper the overall national growth rate.
Reasoning: In order to arrest the accentuation of regional and social disparities, the Planning Commission introduced the ‘target area’ and target group approaches to planning. This is correct. The reasoning explains how the planning process addressed the accentuation of regional and social disparities: by introducing 'target area' and 'target group' approaches.

Does R explains A: The Reason (R) directly explains the "why" and "how" behind the Assertion (A). The Planning Commission adopted these specific strategies precisely to "arrest the accentuation" (stop the worsening) of regional and social disparities. Because the Reason provides the logical methodology used to satisfy the goal mentioned in the Assertion, it is the correct explanation.

NCERT: The planning process has to take special care of those areas which have remained economically backward. As you know, the economic development of a region depends upon its resource base. But sometimes resource-rich region also remains backward. Economic development requires technology, as well as, investment besides resources. With the planning experience of about one-and-a-half decades, it was realised that regional imbalances in economic development were getting accentuated. In order to arrest the accentuation of regional and social disparities, the Planning Commission introduced the ‘target area’ and target group approaches to planning.