I rang you at about ten, but no one answered the phone.A. visited B. was going to visit C. was visiting D. had visited这个选什么

I rang you at about ten, but no one answered the phone.
A. visited B. was going to visit C. was visiting D. had visited
这个选什么

C was visiting
---- I rang you at about ten,but no one answered the phone.
---- Oh,that was probably when I 【was visiting 】 my neighbor.
意思：我大概在十点给你打电话,但是没有人接
噢,那时我可能正在拜访我的邻居.
强调10点的时候发生的事情,用过去进行时.