Which Statement Is Correct

Multiple Choice

Which statement is correct?

A) The placenta secretes human chorionic gonadotropin, estrogen, and progesterone.
B) The placenta serves the functions of the circulatory, respiratory, and digestive systems for the fetus.
C) Maternal and fetal blood are mixed together within the placenta.
D) The placenta secretes human chorionic gonadotropin, estrogen, and progesterone and serves the functions of the circulatory, respiratory, and digestive systems for the fetus.
E) None of these.