Micronutrients Are Needed in Very Small Amounts Because

Micronutrients are needed in very small amounts because

A) most of them are mobile in the plant.
B) most serve mainly as cofactors of enzymes.
C) most are supplied in large enough quantities in seeds.
D) they play only a minor role in the growth and health of the plant.
E) only the most actively growing regions of the plants require micronutrients.