Which of the following might explain why most people are sick more often as children than as adults in their 20s through 50s?
A) The immune system does not appear until the preteen years.
B) The thymus is so active in children that it fights bacteria so hard that it produces strong symptoms of disease.
C) Because of their small size, children's bodies cannot contain as much lymphoid tissue as those of adults.
D) We build up many varieties of memory lymphocytes during childhood, providing immunity to more and more antigens during adulthood.

Question

Quizplus · Accepted Answer

Building up memory lymphocytes during childhood provides immunity to more and more antigens during adulthood, therefore, most people are sick more often as children than as adults in their 20s through 50s.

Which of the Following Might Explain Why Most People Are