Consider the Following to Answer the Question(s) Below

Multiple Choice

Consider the following to answer the question(s) below:
To determine whether the tip left at the end of a meal is related to the size of the total bill at their restaurant, Chez Michelle, data were gathered for 10 customers. The data and summary statistics are shown below.

-A supermarket chain gathers data on the amount they spend on promotional material (specials, coupons, etc.) and sales revenue generated each quarter. The predictor variable is

A) sales revenue.
B) amount spent on promotional material.
C) number of coupons offered.
D) supermarket chains.
E) number of quarter.