How is the entire noun clause used in the sentence?

She saw what was an amazing collection of marine life in the tide pool.

A.
subject

B.
predicate nominative

C.
object of a preposition

D.
direct object

Question

How is the entire noun clause used in the sentence? 

She saw what was an amazing collection of marine life in the tide pool.
	
	
 
A.
	subject
	
 
B.
	predicate nominative
	
 
C.
	object of a preposition
	
 
D.
	direct object

gamer56 · Answer

To my presumption, the noun clause "what was an amazing collection of marine life in the tide pool." 
is the Direct Object of the principal verb "saw" of the Main clause. "She saw"