The "bullwhip effect" is a global phenomenon that refers to$...$

a$.$

When inventories exhibit wild swings up and down because of order amplification. This is due to poor visibility of customer demand along the supply chain.

b$.$

When customers are forced to return merchandise due to errors in order taking.

c$.$

Suppliers are physically beaten and charged fees for errors in order fulfillment.

d$.$

Suppliers shrink inventories to save on expenses and are caught short.