Millets are primarily grown in Tamil Nadu’s:

Coastal plains
River deltas
Dry interior regions
Hilly areas

The correct answer is: c) Dry interior regions.

Millets are a group of cereal crops that are drought-tolerant and can grow in dry, infertile soils. They are a staple food in many parts of the world, including India. In Tamil Nadu, millets are primarily grown in the dry interior regions of the state. These regions are characterized by low rainfall and high temperatures. Millets are well-adapted to these conditions and can produce good yields even in years with low rainfall.

The other options are incorrect for the following reasons:

  • Option (a), Coastal plains: Millets are not well-suited to the coastal plains of Tamil Nadu, which are characterized by high rainfall and humid conditions.
  • Option (b), River deltas: Millets can be grown in river deltas, but they are not as well-suited to these areas as other crops, such as rice.
  • Option (d), Hilly areas: Millets can be grown in hilly areas, but they are not as well-suited to these areas as other crops, such as maize.