Which gland is most active during the early years of life and plays a critical role in the development of a child's immune system? select one of the options below as your a. adrenal gland b. ovaries c. thymus gland

The "Thymus gland" is the choice among the choices given in the question that is most active during the early years of life and plays a critical role in the development of a child's immune system. The correct option among all the options that are given in the question is the third option or option "C".

Both the adrenal gland and thymus gland are important to a developing child, from the nurturing of the child in the ovaries. However, the thymus becomes more important as it plays a critical role in the development of a child's immune system. The answer here is C. thymus

It is evolution, because we all have some of the same traits like eye color or shape or ears.