Farakka agreement between Bangladesh and India implies

Answer: (a) Sharing of river water of Ganges

The Farakka agreements govern sharing of Ganga water in the dry season.

The idea

An upstream diversion affects how much river water remains for a downstream country. A water-sharing agreement allocates that flow, especially during the dry season. This 1991 question predates the 1996 Ganga treaty, so the later treaty must not be treated as the agreement then in force.

Ganga reaches Farakka → Part of the flow is diverted towards the Bhagirathi–Hooghly → Remaining flow continues towards Bangladesh → Dry-season supply becomes a shared concern → India and Bangladesh negotiate water allocation

Also know

The Bhagirathi–Hooghly flows through West Bengal towards the Bay of Bengal; the Ganga continues into Bangladesh as the Padma. Earlier Farakka arrangements preceded the 1996 treaty. Teesta is a different shared river and must not be substituted for the Ganga in this question.