I think the answer is C, because if they are speaking clearly then people can fully understand what they are saying.
An archetypal hero is the character who is admired because he or she exemplifies things that are important in his or her particular culture. For example, an American hero is expected to be honest, strong, patriotic, and diligent.
Not combined with other word parts
C. podium because a podium is an OBJECT and NOT an adjective. ;-)
I hope I helped! =D