The correct answer is: A. The given verb form is correct.
The sentence “My grandparents have got married in London” is in the present perfect tense. The present perfect tense is used to talk about things that have happened in the past but have a connection to the present. In this case, the speaker is talking about their grandparents’ marriage, which happened in the past but is still relevant to the present because the grandparents are still married.
The verb “get” can be used in a number of different ways, but in this case it is being used as a past participle. The past participle of “get” is “got,” and it is used to form the present perfect tense.
The other options are incorrect because they do not use the correct verb form. Option B uses the simple past tense, which is not appropriate for this sentence. Option C uses the past perfect tense, which is used to talk about things that happened before another event in the past. Option D uses the present tense, which is not appropriate for this sentence because it does not talk about something that is happening now.