---I rang you at about ten,but there was no reply.---Oh,that was probably _________ I was seeing the doctor.A.when B.why C.what D.that给的是A 为什么?D项错在哪?

---I rang you at about ten,but there was no reply.---Oh,that was probably _________ I was seeing the doctor.A.when B.why C.what D.that给的是A 为什么?D项错在哪?
---I rang you at about ten,but there was no reply.
---Oh,that was probably _________ I was seeing the doctor.
A.when B.why C.what D.that
给的是A 为什么?D项错在哪?

---I rang you at about ten,but there was no reply.---Oh,that was probably _________ I was seeing the doctor.A.when B.why C.what D.that给的是A 为什么?D项错在哪?
that引导定语从句
定语从句修饰的必须是名词或代词
that,was probably都不是 所以不能是d
从句中主谓宾都齐全,因此应该填关系副词,why语义不通,what= the thing that,语义还是不通,when 是时间关系副词,我那时正在看医生,上下文连贯所以选a