B .The membrane is what separates, and is the system boundary.<span />
The correct answer is "antidepressant drugs".
Antidepressants are drugs commonly used to treat depression, anxiety and phobias, and obsessive-compulsive disorders. There are many different types of antidepressants which differ based on their mechanisms. All of them target the serotonergic system of the human brain. They are not considered addictive but they can cause many different negative side effects.
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Immunotherapy, also called biologic therapy, is a type of cancer treatment that boosts the body's natural defenses to fight cancer. It uses substances made by the body or in a laboratory to improve or restore immune system function. Immunotherapy may work by:
Stopping or slowing the growth of cancer cells
Stopping cancer from spreading to other parts of the body
Helping the immune system work better at destroying cancer cells
There are several types of immunotherapy, including:
Monoclonal antibodies and tumor-agnostic therapies
Non-specific immunotherapies
Oncolytic virus therapy
T-cell therapy
Cancer vaccines
Hope this helped :)