In their advertisements, the manufacturers of a certain brand of breakfast cereal would like to claim that eating their oatmeal for breakfast daily will produce a mean decrease in cholesterol of more than 10 points in one month for people with cholesterol levels over 200. In order to determine if this is a valid claim, they hire an independent testing agency, which then selects 25 people with a cholesterol level over 200 to eat their cereal for breakfast daily for a month. The agency should be testing the null hypothesisH₀: = 10 and the alternative hypothesis:

A)	Ha: < 10.
B)	Ha: >10.
C)	Ha: 10.

Why is the alternative not less than here? Is the null not greater than 10?