D. Immune System
Reproductive system is an obvious wrong answer, nervous system works with your nerves, and muscular is strength.
D- are all living things and bacteria is living
A) Autotrophs because heterotrophs don't make their own food and rely on other organisms while autotrophs are organisms such as plants who use photosynthesis to make their own food.
Answer:
Growth hormone
Explanation:
It is called growth hormone or somatotropin or peptide hormone because it is a substance that control and is responsible for the growth and development of some essential Tissues and cells in the body.
It is secreted by the anterior lobe of the pituitary gland located at the base of the brain.
The growth hormone help children grow taller,increase body mass and help reduce body fat.
The brain keeps you balance and it keeps the heart beating in you don't even think about it because The brand is smart and it could work your body without even thinking about it