Read the sentence. Gregor watched, assessing how Sasha was reacting to his news. Which statement best explains how the underlined clause conveys meaning? It is an adverbial clause explaining Sasha's behavior. It is a noun clause indicating what Gregor was doing. It is a noun clause specifying what Sasha was responding to. It is a relative clause describing the information Gregor gave Sasha.

It is a noun clause indicating what Gregor was doing.

The noun clause says what Gregor is watching. We know that it's a noun clause because it takes the place of a noun. For example, if you were to write the sentence "Gregor watched the dog", it would be a complete sentence and dog is a noun. This is an easy way to check. The clause doesn't answer how he was watching. If it did, it'd be an adverbial clause. The purpose of the clause is not to tell what Sasha is doing since we aren't actually told what her reaction is or what news she's responding to.

It was a noun clause indicating what Gregor was doing.