The correct answer is C. Were / was / was.
The verb tense in the sentence is past simple. This is because the sentence is about a specific event that happened in the past. The event is that the speaker and Roger got married. The speaker was 18 years old when they got
married, and Roger was 20 years old.Option A is incorrect because the verb “are” is in the present tense. The sentence is not about something that is happening now, but about something that happened in the past.
Option B is incorrect because the verb “is” is in the present tense. The sentence is not about something that is happening now, but about something that happened in the past.
Option D is incorrect because the verb “am” is in the present tense. The sentence is not about something that is happening now, but about something that happened in the past.
I hope this helps!