Answer: option B.
The nervous system signals the endocrine system to release
hormones in response to a stimulus.
Explanation:
The nervous system respond to stimulus through action potentials and neurotransmitters and they signals the endocrine system to secrete hormones.
The endocrine system is responsible for secreting hormones into the blood which is transported to the target cells. These hormones are responsible for metabolism , growth and response to stress. The hormones secreted provide feedback to the brain so as to affect neural processing.
Through the blood flow and veins in your body
Ash can be harmful to an environment. It mostly depends on how much ash there is though. If a volcano erupted such as Mt. St. Helen's then yes that can harm an environment. Ash can cover the sky and block out the sun for days before disappearing and that will affect the life of plants
The amount of stuff that an ecosystem