Choose the sentence which contains an indirect object.
a. i worked hard each day.
b. i spent it immediately.
c. they gave me a bonus.
d. it is difficult to save money.

An indirect object is the beneficient of the action, or for whom the action is done. It often has the form of "for x" or "to x", but not always.

Among the options the indirect object is found in the option C:
C. They gave me a bonus.
 the indirect object is "me"