Which of the following statements about human pregnancy and fetal development is false?
(a) The blastocyst is a stage in fetal development that appears early during the third trimester.
(b) A vital connection between the fetal and maternal blood supplies occurs at the placenta.
(c) Most of the growth in fetal size occurs during the second and third trimesters.
(d) All major organ systems have formed by the end of the fetus’s first three months of life.
