Select the option that can be used as a one-word substitute for the given phrase.
Waver between different opinions or actions

Correct option is D

The correct one-word for the given group of words is (d) Vacillate.
Vacillate: To be indecisive; to alternate or waver between different opinions or actions. (दुविधामेंहोना)
Example: She tends to vacillate when choosing what to wear for parties.

Meanings of the given other options:
· (a) Sway: Move slowly back and forth. (झूलना)
· (b) Viaduct: A long bridge carrying a road/railway over a valley. (पुल या पुलनुमा संरचना)
· (c) Thrifty: Using money/resources carefully. (मितव्ययी)