—When did your uncle arrive       China?

—He got to Guangzhou       the morning of the 16th of April.

—When did your uncle arrive ____ China?
—He got to Guangzhou   ____ the morning of the 16th of April

1. A.
   at; in
2. B.
   in; in
3. C.
   to; on
4. D.
   in; on