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 third program provides families with $50 in food stamps each week, redeemable for both perishable and nonperishable food. the fourth policy instead provides a family with a box of nonperishable foods each week, worth $50. use two graphs to illustrate that a family may be indifferent between the two programs, but will never prefer the $50 box of nonperishable foods over the $50 in food stamps. state your answer and use a consumer choice model for perishable food and nonperishable food to graphically justify your choice.