What's the difference between OB and GYN?

Correct answer option B - production of estrogen.

Increase in the production of estrogen is seen in pregnancy and this leads to an increase in vaginal secretion known as leukorrhea.

In pregnancy, the increase in estrogen cause hyperplasia of mucosa glands this cause the increase in vaginal secretions.

Metabolic rate increases in pregnancy but it is not the cause of the increase in vagina secretion, the function of bathorlin gland is to secrete vaginal fluid that lubricates the vagina but it is not the cause of leukorrhea in pregnancy. Option D - supply of sodium chloride to the cells of the vagina is wrong.