Step 1: A tax on imports is an example of a trade barrier, i.e. a restriction used by the government to regulate foreign trade. Step 2: A tariff makes the imported goods costlier in the domestic market, so buyers prefer the goods produced within the country. Step 3: The Indian government, after Independence, had put barriers to foreign trade and foreign investment precisely because the industries were just coming up in the 1950s and 1960s and competition from imports at that stage would not have allowed them to grow. Step 4: Hence tariffs are imposed to protect local (domestic) industries - Option (B).