Which of the following idiom given in the alternatives has the meaning?
Enjoy oneself very much

Correct option is C

The correct option is (c).

Explanation:
Option (c) is the correct meaning of the given idiom.
Have a whale of a time: To enjoy yourself very much; to have an exceptionally fun or exciting experience. (बहुत मज़ा करना)
Example: The kids had a whale of a time at the amusement park.

Other related idioms:

• In the nick of time: At the last possible moment.
• Time of your life: A period of exceptional enjoyment.