The Parents of a Client Recently Diagnosed with Down Syndrome

The parents of a client recently diagnosed with Down syndrome relate to the nurse that they "feel guilty about causing the condition." Which response by the nurse is the most appropriate?

A) "Down syndrome is a condition caused by an extra chromosome; the cause of it is unknown."
B) "Down syndrome is a condition that is genetically transmitted from both the father and the mother."
C) "Down syndrome is a condition that is carried on the X chromosome, so it came from the mother."
D) "Down syndrome is caused by birth trauma, not by genetics."