Huntington disease tends to strike earlier and lead to a more rapid progression of symptoms as it moves from generation to generation. Also, it tends to strike earlier and progress more rapidly when it is passed from the father to his children rather than from the mother. Which generic phenomenon ( or phenomena) is (are) likely operating here?
A) incomplete penetrance
B) sex-limited inheritance
C)genetic anticipation
D)parental imprinting
E)more than one of the above.