Answer:
The student in the back of the room knows all the answers but never raises her hand.
Step-by-step explanation:
They're all pretty bad sentences honestly, theres much better ways to write all of this, but all those expect the one I mentioned sound wrong to me. If i had to convey the same message in a sentence, I'd say " The student at the back of the classroom knows all the answers but refuses to raise her hand." or "The student at the back of the classroom knows all the answers but never raises her hand."