Answer:
A.
Explanation:
Dependent clauses cannot stand on their own as sentences, usually because of a specific word that subordinates them to the main clause of the sentence. In this case, "because" is the word that makes "I was sleepy" a dependent clause. All other options can be full sentences because they don't depend on anything else for full meaning.
B
Explanation: It just is lol
I’d say D. is the best choice
Hope this helps you
-AaronWiseIsBae