Which of the following is not true of the Rh factor?

A)It is an antigen found on some people's red blood cell membranes.
B)A high percentage of Americans have the Rh factor.
C)The most reactive of the Rh antigen group is antigen B.
D)It was named for the Rhesus monkey, in which it was first discovered.
E)All of these are true of the Rh factor.