Why is the flow of Narmada and Tapi considered different from many peninsular rivers?

Correct answer: They flow westward into the Arabian Sea

The governing concept is the drainage pattern of Peninsular India. Most major peninsular rivers, such as the Mahanadi, Godavari, Krishna and Kaveri, generally flow eastward toward the Bay of Bengal. Narmada and Tapi are notable exceptions: they flow westward through structural troughs or rift-valley settings and enter the Arabian Sea. Thus option C is correct. They do not flow north into the Himalayas, do not form deltas in the Ganga Plain, and do not end only in lakes. Their westward direction and distinctive valley setting explain the contrast.