Null hypothesis problem

#1
I need help with this problem. Not sure if I chose the right answer.

Express the null hypothesis HO and the alternative hypothesis H1 in symbolic form. Use the correct symbol for the indicated parameter.
The manufacturer of a refrigerator system for beer kegs produces refrigerators that are supposed to maintain a true mean temperature of 41 degrees F, ideal for a certain type of German pilsner. The owner of the brewery does not agree with the refrigerator manufacturer, and claims he can prove that the true mean temperature is incorrect.

u = mean

The choices are:

A) HO: u not equal to 41
H1: u = 41

B) HO: u less than or equal to 41
HI: u is greater than 41

C) HO: u is greater than or equal to 41
H1: u is less than 41

D) HO: u = 41
H1: u is not equal to 41

The answer I chose was A because it states that the null hypothesis does not equal 41 and the owner of the brewery did not agree with the refrigerator manufacturer about the refrigerator maintaining a temperature of 41 degrees and the alternative hypothesis is equal to 41 because the manufacturer felt the refrigerator would maintain a temperature of 41.