Which is a sentence fragment? a. because i spent three hours on my homework. b. i'll probably find it somewhere in my backpack. c. the assignment disappeared off my hard drive. d. i am frustrated so i deleted the entire thing.

The answer is A. Because I spent three hours on my homework.

This fragment provides a verb statement, but there is no subject preceding this statement. A sentence must have a subject-verb agreement to be considered a sentence. Without one or the other, it is a sentence fragment.