What is the exact wording of the question? If it contains "how far", or "to what extent", you can argue the opposite, that the black consciousness movement did not have a great influence on the American civil rights movement.

Have you asked your teacher for further clarification? That's usually the first step if you have any confusion about assignments. It's possible that you've misunderstood some aspect of the question. You may want to tell your teacher that you are having difficulty finding sources and that you would like help with the names of historians or texts to research from. If they cannot produce any... well, that's an entirely different matter then.

Additionally, you may want to ask your classmates whether they are having the same problem. It's likely that they are, and having the collective power of the class sets you up nicely for the most probable outcome - the students going up the administrative ladder and formally complaining about/contesting the teacher's assignment.