Which of the Following Statements Best Explains Why Young Children

Multiple Choice

Which of the following statements best explains why young children develop infections more often than older children and adolescents?

A) Cell-mediated immunity doesn't achieve full function until a child is roughly 5 years old.
B) The thymus doesn't begin to function until adolescence, so prior to this time, children don't produce enough T cells to adequately protect them from infectious agents.
C) Children don't develop all of the immunoglobulins they need to protect against infection until they are about 6 or 7 years of age.
D) Young children have comparatively small lymphoid tissues, which means they are less able to fight infection than are older children.