The correct answer is: a) Coastal Plains
Black soil is a type of soil that is rich in organic matter and nutrients. It is well-drained and has a high water retention capacity. This makes it ideal for growing crops such as cotton.
The Coastal Plains of Odisha are the most fertile region of the state. They are located in the eastern part of the state, along the Bay of Bengal. The soil in this region is predominantly black soil, which is ideal for cotton cultivation.
The Northern Plateau of Odisha is a hilly region. The soil in this region is not as fertile as the soil in the Coastal Plains. It is also not as well-drained, which makes it less suitable for cotton cultivation.
The Western Undulating Uplands of Odisha are a hilly region. The soil in this region is not as fertile as the soil in the Coastal Plains. It is also not as well-drained, which makes it less suitable for cotton cultivation.
The Eastern Ghats are a mountain range that runs along the eastern coast of India. The soil in the Eastern Ghats is not as fertile as the soil in the Coastal Plains. It is also not as well-drained, which makes it less suitable for cotton cultivation.