Which of the Following Statements About Teratogens Is True

Which of the following statements about teratogens is true?

A) During the last few months of pregnancy, teratogens have minimal impact on the fetus.
B) Teratogens always result in observable birth defects, such as facial or limb deformities.
C) The effects of exposure to drugs or alcohol are universal and primarily influenced by genetic factors.
D) Different teratogens can cause the same birth defect, and a variety of birth defects can result from the same teratogen.