I can’t remember the exact date when Smiths came to see him but it was Sunday.A a the B

问题补充：

I can’t remember the exact date when Smiths came to see him, but it was Sunday.

A a, the B the, a C a, a D the, the

答案：

解析：考察冠词用法。前文特指史密斯一家，故用定冠词，下文泛指任何一个星期日，故用不定冠词，选B。