You Have Accidentally Bumped into Someone, and This Person Responds

You have accidentally bumped into someone, and this person responds in anger that "You fool, you should watch where you are going.You could have hurt me!" To respond assertively, you should

A) become very angry and call this person names also.
B) point out that you did not bump into him; that he is the one that should be apologizing since he bumped into you.
C) apologize, acknowledge his anger, but explain that there was no reason to call you names, since you did not bump into him intentionally.
D) apologize profusely and leave the area immediately.