Answer:
A concussion is a complex physiological process induced by a bump, blow, or jolt to the head or body, transmitting a force that causes the brain to literally bounce around or twist within the skull.
Explanation:
The damage done to the brain is at a microscopic level: cells and cell membranes are stretched and torn.
<em>Hope this helped :)</em>
I believe the answer is a.
Carcinogens is a substance capable of causing cancer in living tissue.
Answer is: cancer causing agents
