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.
The answer to this is D. When this happens, the nurse should know that the patient is going to give birth soon. Expelling of clear vaginal fluid may occur during the first stage of labor. It may even signify that labor is already starting. The contractions may start since then and a regular labor would become more frequent as the mother goes nearer into giving birth.
The rupture of the membranes also occurs during the first stage of labor which means that the only option is D. This usually ends when the mother finally gives birth to her child. A child who has been properly trained for this situation will be able to determine the proper signs.