Which explanation is the correct one? (1)

Hi teachers,
According to this sentence, "Sharon has had dinner with Robert three times."
Which explanation is the correct one? I guess it is letter 'a'. Could you confirm or correct it?
a) Because of the tense and the adverb of number, the sentence informs on the exact number of times with which Sharon has had dinner with Robert at indefinite points in time in the past up to now.
b) Because of the tense and the adverb of number, the sentence informs on the exact number of times Sharon has had dinner with Robert at indefinite points in time in the past up to now.

Thanks in advance.