He could not understand the judges awarding her the first prize, because he thought that her performance was quite ______.

superb

exhilarating

medium

mediocre

The context of the sentence requires a word that will express the contradiction in the speaker’s mind

Since he did not think the performance to be impressive, that is why he could not understand the reason for her getting the first prize

so,

Mediocre معمولی is used as an adjective (to represent quality) and means low in performance

and D is the correct choice.

ND11-2-2023