Which one of the following groups of plants was domesticated in the 'New World' and introduced into the 'Old World'?

Option (a) is correct because tobacco, cocoa, and rubber are all indigenous to the Americas (New World) and were introduced to Afro-Eurasia (Old World) following the Columbian Exchange. Option (b) is the most tempting distractor, but it is incorrect because cotton has ancient origins and was already widely cultivated in the Old World (notably the Indus Valley) long before the discovery of the Americas. This question tests the core concept of the Columbian Exchange and the historical-geographical origins of major global crops.