The correct answer to the question is option 2: South America. The cashew tree was introduced to India by the Portuguese in the sixteenth century, and it was brought from South America.

Option 1: U.S.A.

This option is incorrect because the cashew tree was not brought from the USA. The cashew tree is not native to the United States.

Option 3: Africa

This option is also incorrect because the cashew tree was not brought from Africa. The cashew tree is native to Brazil and other countries in South America, not Africa.

Option 4: Europe

This option is incorrect because the cashew tree was not brought from Europe. The cashew tree is not native to Europe and was not introduced to India from Europe.

In conclusion, the cashew tree was brought to India from South America by the Portuguese in the sixteenth century.