With reference to Peninsular India, consider the following statements:

a. Dodabetta is the highest peak of Peninsular plateau located on the Western Ghats.

b. Karbi-Anglong plateau is an extension of peninsular plateau.

c. Peninsular rivers are characterised by fixed course, defined meanders and non-perennial flow of water. 

d. It is mostly composed of igneous and metamorphic rocks.

Which among the following statements is/are correct?