The district famous for red sandalwood forests is:

The correct answer is: a) Kadapa.

Kadapa district is famous for its red sandalwood forests. Red sandalwood is a rare and valuable wood that is used in making furniture, musical instruments, and other luxury items. The forests in Kadapa district are home to a large population of red sandalwood trees, which are protected by the government.

The other options are incorrect because they are not districts that are famous for red sandalwood forests. Chittoor district is famous for its temples, Nellore district is famous for its mangoes, and Kurnool district is famous for its granite.