Typically,the Sales Volume Declines with an Increase of a Product

Multiple Choice

Typically,the sales volume declines with an increase of a product price.It has been observed,however,that for some luxury goods the sales volume may increase when the price increases.The following Excel output illustrates this rather unusual relationship. What is the number of estimated coefficients of the cubic regression model?

A) 1
B) 2
C) 3
D) 4