Which sentence is an example of present perfect tense?

The present perfect tense is used to describe actions that occurred at an unspecified time before now or actions that started in the past and continue to the present. In this case, the sentence "He has taken training" effectively illustrates the present perfect tense due to the use of "has" along with the past participle "taken." This structure emphasizes the relevance of the completed action (taking training) to the present moment, suggesting that the training has implications for the current situation.

In contrast, the other sentences represent different tenses: the first discusses a completed action in the past (past tense), the second specifies a past action that happened at a clear time (simple past), and the fourth talks about a future action (future tense). Understanding the characteristics of each tense helps clarify why "He has taken training" is the correct choice in this context.