The brain of the nervous system and the endocrine glands of the endocrine system are similar to one another in certain ways. Both act to send messages to distant body parts. What is a significant difference of the activity of endocrine glands?
A. Endocrine glands send chemical messengers through the blood.
B. Endocrine glands send electrical signals through neural pathways.
C. The effects of endocrine glands tend to be short-lasting and easily reversible.
D. The effects of endocrine glands tend to involve only the muscular and skeletal systems.