Question

?Donde esta reloj?

Answer 1

?Donde esta reloj? - B.El reloj esta encima de la puerta. 
This means: Where is the clock? - The clock is near the door.

A means The desk is in the door. C means The desk is under the door. D means The desk is behind the door. 

Answer 2

B. El reloj esta encima de la puerta.