When doctors discuss prenatal development, they often calculate the due date from the first day of menstruation. In fact, the baby’s gestational age is calculated from the first day of menstruation. At a maternity clinic, an obstetrician mentions that when a woman is 10 weeks pregnant, the baby is referred to as a fetus. Which of the following is the correct calculation of the baby’s age from the moment of fertilization, assuming a 28-day ovarian cycle?Select one:

a. The baby is 8 weeks old. This is when organ formation has completed.

b. The baby is 10 weeks old as stated by the doctor.

c. The baby is 12 weeks old and at the end of the first trimester.

d. The baby is in its second trimester. This is when they are referred to as a fetus. I think the answer is d but i'm not 100% sure.