Which statement about positive and negative feedback loops is correct?

• A. Negative feedback always lowers the value of the original stimulus, while positive feedback always increases it.
• B. Positive feedback loops tend return a system to a set-point, negative tend to move the system away. 
• C. Negative feedback loops tend return a system to a set-point, positive tend to move the system away. 
• D. Negative feedback always increases the value of the original stimulus, while positive feedback always lowers it.