Which of the following statements about positive feedback mechanisms is not true?
a. positive feedback mechanisms can result from human activity.
b. positive feedback mechanisms can occur naturally.
c. positive feedback mechanisms lead to increased change.
d. positive feedback mechanisms reduce change in a system

The correct answer is d  the positive feed back reduces change in the the system

Explanation:

In an  biochemical reaction when the released product stimulate the release and activation of the same product and act together to exibit their biological function, then this type of regulation is called positive feedback.

     The positive feed back mechanism leads to increased change in the system that"s why it is named so.

    For example during blood clotting platelets molecules are released to form clots to stop bleeding. one activated platelet can stimulates the activity of other platelets which then join together to form a group for generating further blood clots.

d. Positive feedback mechanisms reduce change in a system

Explanation: :)

we would need to see the picture to answer it