Common Grammar Mistakes - Verb tense

Which is correct?

_________ installing the patches?
a. Did you finish
b. Have you finished

Answer: b

Explanation:

Simple past tense (Did you finish) is used to express a completed action that occurred at a specific moment in the past. Present perfect tense (Have you finished) is used to express something that happened at an unspecified time in the past. Because there’s no mention of a specific time in this sentence, use the present perfect tense.