a complimentary response a control system negative feedback positive feedback
I gave my students this multiple choice question: In a series of chemical reactions, X→Y→Z→A, X converts to Y, Y converts to Z, and Z converts to A. Which term describes the process if the production of A interferes with the conversion of X to Y?

Only one answer is correct among these 4 choices:
- a complimentary response
- a control system
- negative feedback
- positive feedback

Could you tell me which one is correct?

negative feedback