Correct option is C
Explanation of the Correct Answer: · "Mutely" means "without speaking or making a sound."
· The opposite of "mutely" is "loudly" (making a sound).
Why Are the Other Options Incorrect? · (a) "Forcefully" → Incorrect; forceful action doesn’t relate to speaking.
· (b) "Silently" → Incorrect; it is a synonym, not an antonym.
· (d) "Promptly" → Incorrect; relates to time, not sound.
Thus, the correct antonym is (c) "Loudly."