Construction of which of the railway enhanced the connectivity along the western coastal plain of India?

Konkan railway

The correct answer is Option (1) → Konkan railway

The Konkan Railway, completed in the 1998, runs along the western coastal plain of India, connecting Maharashtra, Goa, and Karnataka. It greatly enhanced connectivity in this difficult hilly and coastal terrain.

"One of the important achievements of the Indian Railways has been the construction of Konkan Railway in 1998. It is 760-km long rail route connecting Roha in Maharashtra to Mangalore in Karnataka. It is considered an engineering marvel. It crosses 146 rivers, streams, nearly 2000 bridges and 91 tunnels. Asia’s largest tunnel which is nearly 6.5 km long, also lies on this route. The states of Maharashtra, Goa and Karnataka are partners in this undertaking.".