(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
A is true — agriculture and industry move hand in hand (agro-industries depend on agriculture for raw materials and supply inputs like fertilisers back to farmers). R is also true — industrial development is a precondition for eradicating unemployment and poverty. However, R explains the importance of industrialisation in general, not why agriculture and industry are interdependent. Hence R is not the correct explanation of A. Option (b) is correct.