Which sentence has a noun clause used as its subject A) My watch was really expensive but it also easy to break. B) Glenn regretted that she had never spent time learning play the guitar?

Here's why:

* Noun Clause: A noun clause is a group of words that acts like a noun. It usually starts with words like "that," "what," "who," "where," "when," "why," or "how."

* Subject: The subject of a sentence is the person, place, or thing that performs the action of the verb.

In sentence B, the noun clause "that she had never spent time learning to play the guitar" acts as the direct object of the verb "regretted." The entire clause is what Glenn regretted.

Let's break down why the other sentence is incorrect:

* A) My watch was really expensive but it also easy to break. This sentence has two independent clauses. The noun clause "that it also easy to break" functions as an adjective modifying the pronoun "it." It does not act as the subject of the sentence.