A linear regression was used to determine the linear relationship between the sales of Gulp Milk and the average price for milk across its competitors. If the average competitor price rises or falls, but all other factors remain equal, including the price of Gulp Milk itself, what kind of slope coefficient do we expect to find for this relationship?

A. Positive – at a higher average competitor price, the profits for Gulp Milk are lower

B. Negative – when milk is more expensive, people tend to buy alternatives such as yoghurt

C. Negative – when the average competitor price increases, the sales of all products decrease

D. Positive – when the average competitor price increases, Gulp Milk’s price is relatively lower