Which of the Following Statements About the Father's Role in Transmitting

Which of the following statements about the father's role in transmitting birth defects is correct?

A) So far,little research has been conducted on the father's contribution.
B) According to research,the father's role is virtually nonexistent;birth defects are almost always transmitted by the mother.
C) Young age of the father is associated with certain rare conditions such as dwarfism and Marfan's syndrome,and it may be a factor in Down syndrome.
D) Advanced age of the father at conception may be associated with fetal defects.