Your friend uses marijuana to treat back pain because she believes it is a natural remedy. She wonders if it is ok to continue using marijuana once she gets pregnant. You respond by telling her ______

a. it is ok to continue using marijuana since it is natural
b. it is ok to continue using marijuana because there are no known harmful effects during pregnancy
c. she should stop using marijuana as regularly as she does and cut back on her uses during pregnancy
d. she should stop using marijuana because it could affect the development of the central nervous system and slow the growth of the fetus

Answer: D