Firm A is selling a product for $40, while their major competition is selling the same product for $50. Firm A is trying to decide whether to market their price as "$10 off" or "20% off." According to the majority of research, which strategy would be the most effective?
A. They will be equally effective
B. 20% off
C. There is no way to determine effectiveness
D. $10 off
Answer: B