This is the sixth time that the monthly GST collection is the highest since the ____________of GST.

Correct option is D

The correct word for the given blank is ‘inception’
(a)interim means the intervening time.
(b)prompt means cause or bring about (an action or feeling).
(c)doable means within one's powers; feasible.
(d) inception means the establishment or starting point of an institution or activity.
(e)dissent means the holding or expression of opinions at variance with those commonly or officially held.