OPTIONS: (I). it needs them. (II). cells. (III). Plants growth. (IV). messengers. (V). positive. (VI). infections. (VII). kinetic. (VIII). disease.
Q: Fact 1: Hormones are chemical messengers that control many body functions. Fact 2: Hormones are a functional class of chemicals. Given the two facts above, what are hormones?
A:
(IV).