When injected, benzedrine, dexedrine, and methamphetamine increase the release of serotonin, norepinephrine, and dopamine in the brain. Benzedrine, dexedrine, and methamphetamine are examples of amphetamines. They are stimulants, which speed up the messages travelling between the brain and the body. They may be used to treat attention deficit hyperactivity disorder.
The function of the central vacuole is to maintain proper pressure within the plant cells to provide structure and support of the growing plant.
The skin functions as a barrier to prevent the entry of microorganisms.
Unicellular organisms are living things made up of only one cell. For example, bacteria and yeast are unicellular. Multicellular organism are made up of more than one cell. Some examples of a multicellular organisms are humans and animals.
I believe the answer is A.