Which of these is an example of negative feedback?
As a blood clot begins to form, the process of its formation gets faster and faster.
After you eat, glucagon stimulates an increase in blood sugar levels.
After you eat, insulin stimulates the lowering of blood sugar levels.
The digestive enzyme pepsinogen is converted to pepsin by the action of hydrochloric acid; pepsin itself can then convert pepsinogen into pepsin.
Once labor begins, contractions increase in frequency and intensity.