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.
direct object

b.
subject

c.
object of a preposition

d.
predicate nominative

moon-letters were a method of writing invented by the dwarves. moon-letters were ordinary runes, but written in such a way that they could only be read when the light of the moon shone behind the writing. some moon-letters could be read by any moonlight, but it was possible to make the writing even more secret. more sophisticated moon-letters could only be read by the light of the same shape of moon, or at the same time of year, as when they were written. hope this !

i think she wanted to protect her children from the extreme racism of the american south.