Let's match the coastal plains (List-I) with their corresponding states (List-II).
a. Konkan Coast: This is the northern part of the western coast of India, stretching along the states of Maharashtra and Goa. So, a matches with 4.
b. Canara Coast: This is the central part of the western coast, primarily located in the state of Karnataka. So, b matches with 1.
c. Malabar Coast: This is the southern part of the western coast, extending along the state of Kerala. So, c matches with 2.
d. Coromandel Coast: This is the coastal plain on the eastern side of India, stretching along the state of Tamil Nadu. So, d matches with 3.
The correct matching is a-4, b-1, c-2, d-3.
This corresponds to option (D).