Read the sentence.

Colin has volunteered at the animal shelter at least three time.

Which verb tense does the sentence contain?

A. Past

B. Past perfect

C. Present

D. present perfect

The answer is: D. present perfect

The Present Perfect tense is formed with the auxiliary verbs has or have, followed by the past participle. It is usually used to talk about experiences at an indefinite time in the past.

The rest of the options are incorrect because the verb volunteer in the past form is volunteered; in the past perfect it is had volunteered, and in the present simple tense it would be (Colin) volunteers.

I think it is present perfect.