The answer is d.) Colostrum.
Explanation for each option:
a.) Foremilk: This is the milk that is released at the beginning of a breastfeeding session after the initial days postpartum. It is not secreted within the first 48-72 hours.
b.) Transitional milk: This type of milk is produced after colostrum and before mature milk, typically starting around the third to fifth day postpartum, not within the first 48-72 hours.
c.) Hindmilk: This is the milk that comes later in a breastfeeding session, after foremilk, and is richer in fat. It is not secreted within the first 48-72 hours postpartum.
d.) Colostrum: This is the first form of milk produced by the mammary glands immediately following delivery. It is secreted within the first 48-72 hours postpartum and is rich in antibodies and nutrients essential for the newborn.
Summary: Within the first 48-72 hours postpartum, the breasts secrete colostrum, which is crucial for the newborn's initial nutrition and immune protection.