Select the most appropriate meaning of the highlighted idiom.
Everybody was surprised to see that he fell flat even after arduous efforts.

Correct option is C

The correct meaning of the idiom is Fail to win applause.
Given Idiom:
"Fell flat" means to fail completely or to not produce the desired effect. (हिंदी अर्थ: पूरी तरह विफल होना)
Example:
His joke fell flat, and nobody laughed.
Other related idioms and their meanings:
· Hit the nail on the head: Do something exactly right.
· Miss the mark: Fail to achieve the goal.
· Go off track: Deviate from the main purpose.