Hub.com is considering a new product called A-Plus for its customers. However, the introduction of this new product is expected to lower the revenues received from Hub.coms existing lines of products by $100,000 per month. The lowered revenues are considered

Select one:

a. a sunk cost.

b. an opportunity cost.

c. a side effect.

d. an erosion.

e. b, c, and d are all correct.