The correct options are
C Deltas are formed by rivers in the Western coastal plain.
D Backwaters and estuaries are seen on the Eastern coastal plain.
Deltas are formed on the Eastern coastal plain whereas backwaters and estuaries are seen on the Western coastal plain. The Western coast can be divided into Gujarat coast, Konkan coast and Malabar coast. The Eastern coastal plain runs from the Sunderbans to Kanyakumari.