The correctly matched pair is:
A — Gandhi Sagar — Chambal
Gandhi Sagar Dam is built on the Chambal River in Madhya Pradesh. (Hirakud is on Mahanadi; Nagarjuna Sagar is on Krishna; Salal is on Chenab.)
Source: Water Resources, Chapter 3
The textbook mentions Hirakud on the Mahanadi basin, which rules out option B. Nagarjuna Sagar is on the Krishna River (not Kaveri), ruling out C. Salal Project is on the Chenab River (not Beas), ruling out D. Gandhi Sagar on Chambal is the only correct match. Examiners expect you to know the correct river-dam pairing for all major multipurpose projects.