The answer is...
B. Buffers
Answer:
True
Explanation:
Those are systems in your body
The femur is not part of the circulatory system because it is a bone.
Answer by JKismyhusbandbae: stimulant.
Depressants are drugs that slow the central nervous system. Depressants are widely used and inhibit the function of the central nervous system also known as stimulant.