When Children Are Participants in a Research Study

When children are participants in a research study:

A) consent is needed from their parents only.
B) there is no need to obtain informed consent from the children because they are unable to give legal consent.
C) even though parental consent is legally sufficient, the assent of the children should be obtained as well.
D) obtaining the consent of children would be unwise because it would alert children that they are being studied and they would then behave differently.
E) informed consent is not required because children are too young to understand.