The hormone responsible for maturation of mammary gland tissue is:

Choice A reason: This is not the main reason, as the use of contraceptives for an extended time does not necessarily affect the fertility of a woman. Most contraceptives are reversible and do not cause permanent damage to the reproductive system. However, some contraceptives may take longer to wear off than others, and some may have side effects that can interfere with ovulation or implantation.

Choice B reason: This is the main reason, as the aging process can affect the ovaries and the quality and quantity of the eggs. As a woman ages, her ovarian reserve (the number of eggs in the ovaries) declines, and the eggs become more prone to chromosomal abnormalities. This can reduce the chances of conception and increase the risk of miscarriage or birth defects.

Choice C reason: This is not the main reason, as prepregnancy medical attention is not a prerequisite for achieving pregnancy. However, prepregnancy medical attention can be beneficial for a woman who is older than 35 years, as it can help identify and manage any existing or potential health problems that may affect the pregnancy, such as diabetes, hypertension, or thyroid disorders.

Choice D reason: This is not the main reason, as personal risk behaviors are not specific to a woman who is older than 35 years. Personal risk behaviors are factors that can negatively affect the fertility of any woman, regardless of age. Some examples of personal risk behaviors are smoking, drinking, using drugs, having multiple sexual partners, or having sexually transmitted infections.

Choice A reason:

Nagele's rule for calculating the estimated date of confinement (EDC) involves subtracting 3 months from the first day of the last menstrual period and adding 7 days. For February 13th, subtracting 3 months gives us November 13th, and adding 7 days gives us November 20th. This is the most accurate calculation for the estimated date of confinement.

Choice B reason:

This choice is not accurate according to Nagele's rule. Adding 7 days to November 13th would give November 20th, not November 27th.

Choice reason:

This choice is not accurate according to Nagele's rule. Adding 7 days to November 13th would give November 20th, not November 21st.

Choice D reason:

This choice is not accurate according to Nagele's rule. Subtracting 3 months from February 13th would give November 13th, not November 14th.