How is the underlined pronoun used in the subordinate clause?

That's the boy whom I saw at the swimming pool today. ( Whom is underlined)

A.
subject

B.
indirect object

C.
object of a preposition

D.
direct object

Question

How is the underlined pronoun used in the subordinate clause? 

That's the boy whom I saw at the swimming pool today. ( Whom is underlined) 
	
	
 
A.
	subject
	
 
B.
	indirect object
	
 
C.
	object of a preposition
	
 
D.
	direct object

anonymous · Answer

I figuerd this out i think it's subject but now i have the last one i need help with

calculusxy · Answer

Okay

calculusxy · Answer

So what is the question ?

anonymous · Answer

sorry my computer froze @calculusxy