Select the most appropriate option to fill in the blank.
They prefer tea ______ coffee.

Correct option is C

The correct option to fill in the blank is (c) to.
After prefer, the standard preposition is to: prefer X to Y. Hence, “They prefer tea to coffee” is correct. (Hindi: prefer X to Y = X को Y पर तरजीह देना)
Example: She prefers reading to watching TV.
Explain why other options are incorrect:
• power — unrelated noun; semantic misfit. (Hindi: शक्ति)
• than — used after comparative adjectives/adverbs, not after prefer in this structure. (Hindi: से)
• from — indicates source/separation; wrong here. (Hindi: से)
Info booster: Alternative correct patterns include prefer + gerund to + gerund (e.g., walking to running) and * would rather + base verb (than + base verb) (e.g., I’d rather walk than run).