The correct answer is option 4, Portuguese. The Portuguese were the ones who introduced cashew nut, pineapple, and tobacco into India. This happened during their colonial rule in the 16th century. The Portuguese traders and explorers brought these commodities from their colonies in Brazil and other parts of the world to India. They established trade routes and settlements along the western coast of India, particularly in regions such as Goa and Kochi.

The introduction of cashew nuts, pineapple, and tobacco by the Portuguese had a significant impact on Indian agriculture and trade. Cashew nuts became an important cash crop in parts of coastal India, especially in Goa. Pineapple cultivation also spread in certain regions of India, adding to the diversity of tropical fruit crops in the country. Tobacco cultivation, on the other hand, gained popularity in certain parts of South India.

Therefore, it was the Portuguese who were responsible for introducing cashew nut, pineapple, and tobacco into India.