A 35-Year-Old Caucasian Primigravida Is Found to Have Gallstones at 38

A 35-year-old Caucasian primigravida is found to have gallstones at 38 weeks of an uncomplicated pregnancy.  Ultrasonography performed one year ago failed to demonstrate any abnormalities.  Which of the following pathogenetic components most likely contributed to this patient's condition?

A) Prolactin-induced phospholipid secretion and progesterone-induced gallbladder hypermotility
B) Prolactin-induced sodium secretion into bile and estrogen-induced gallbladder hypomotility
C) Progesterone-induced bile acid secretion and hCG-mediated water reabsorption from the bile
D) Estrogen-induced bilirubin hypersecretion and cortisol-mediated cholesterol hypersecretion
E) Estrogen-induced cholesterol hypersecretion and progesterone-induced gallbladder hypomotility