Correct Answer: Rehearsal of an event

Solution : The correct answer is the second option.

Explanation : In the context of idioms, a dry run refers to a rehearsal or practice session to test or prepare for a future event. While the individual words dry and run might suggest running without shoes or jogging in a park, the idiom as a whole takes on a different meaning. It implies a trial or practice event conducted without any real consequences or impact, allowing participants to identify and address potential issues before the actual occurrence.

Therefore, the correct meaning of the idiom is, rehearsal of an event.