Correct Answer: Both the assertion and reason are true, and the reason is the correct explanation of the assertion.

Solution : The correct answer is (a) Both the assertion and reason are true, and the reason is the correct explanation of the assertion.

The assertion is true. The Foreign Trade Policy of India during 1951-1991 did indeed focus on import substitution. Import substitution refers to a strategy where a country aims to reduce its dependence on imports by promoting domestic industries and producing goods locally that were previously imported. The policy aimed to build a self-reliant economy by developing domestic industries and reducing imports of finished goods.

The reason is also true. The policy aimed to reduce imports and promote domestic industries. By reducing imports and encouraging the growth of domestic industries, the policy sought to develop a self-sufficient industrial base and reduce the country's reliance on foreign goods. The emphasis on import substitution was driven by the belief that it would promote economic development, protect domestic industries, and reduce foreign exchange outflows.

Therefore, both the assertion and reason are true, and the reason is the correct explanation of the assertion.