I guess you forgot to include the choices so your question could be answered. However, I would still love to help. I could just tell you how to determine which is the answer from the choices that you have.
All you have to do is you divide the mass with the volume since density is mass per unit volume. Be conscious on the units used. If the quotient of the mass and volume measurements equal to 3 gram per cu. cm, then that is the answer.
I hope I was able to help you :)