Naveen Works as a Sales Representative for Rogers Pet Foods

Naveen works as a sales representative for Rogers Pet Foods. He is on a commission plan. His individual performance has been steady over the past few months but he has noticed a decline in his pay. Which of the following is NOT a likely cause for Naveen's pay decline?

A) Changes in the economy.
B) Increased competition from rival pet food suppliers.
C) His intrinsic motivation.
D) Seasonal fluctuations in the demand for pet food.