Yes, it's a dependent clause.
The answer you are looking for is C
It depends on the type of glass you are talking about.
Glass (like a glass of water) is glasses.
If it is like a pane of glass then it would not change you'd just add a plural before it like "two panes of glass".
Hope it helps!
Answer:
noun, pronoun, verb, adjective, adverb, preposition, conjunction, and interjection
Explanation: