Why does a newborn baby need to have received a supply of material antibodies prior to birth?

Antibodies, which are also called immunoglobulins, take five basic forms, denoted as IgG, IgA, IgM, IgD and IgE. All have been found in human milk, but by far the most abundant type is IgA, specifically the form known as secretory IgA, which is found in great amounts throughout the gut and respiratory system of adults.

Explanation:

the index of refraction of the second medium is higher. i just took the test trust me !

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.