The Possibility of Down Syndrome Increases as the Mother's Age

The possibility of Down syndrome increases as the mother's age increases because

A) her DNA is damaged through an accumulation of replication errors.
B) her DNA stops checking for replication errors.
C) fertilization no longer occurs correctly with older eggs.
D) the contents of the egg contain the wrong signals for the correct development of the fetus.
E) the possibility of nondisjunction increases.