--Mr. Li, I found a watch on the playground.
--You should try to find out _________
A. whose is the watch
B. who is the owner of the watch
C. whom does the watch belong to
--Mr. Li, I found a watch on the playground.
--You should try to find out _________
A. whose is the watch
B. who is the owner of the watch
C. whom does the watch belong to