To Produce an Individual with Down Syndrome (47,+21)

Multiple Choice

To produce an individual with Down syndrome (47,+21) ,

A) a nondisjunction event must have occurred during spermatogenesis.
B) more than one sperm must have been involved in fertilization.
C) a nondisjunction event must have occurred during oogenesis.
D) this must have been caused by uniparental disomy.
E) a nondisjunction event could have occurred during spermatogenesis or oogenesis.