A: Have you been to the United States? B: Yes, I ______ in 1989. ?

In the dialogue presented, Speaker A inquires about Speaker B's past experience of visiting the United States, specifically referencing the year "1989." The correct response is "Yes, I went there in 1989," which corresponds to option A.

The reason this is the correct choice lies in the nature of the event being discussed. The phrase "went there" uses the simple past tense, which is appropriate when referring to a specific time in the past, such as "1989." This indicates that the action of visiting the United States was completed in the past.

Option B, "have gone there," employs the present perfect tense, which is used to indicate actions that occurred at an unspecified time in the past, or that have relevance to the present. However, because the question specifies a particular year, this tense is not suitable.

Option C, "have been there," also uses the present perfect tense and suggests an ongoing relevance or experience rather than a completed action at a specific time.

Lastly, option D, "went," is incomplete without a preposition (such as "there") to clarify the destination of the action. Thus, the simple past "went there" precisely captures the intended meaning of the response.