In Comparing the Difference of the Means Between Two Groups,the $\mu_{1}-\mu_{2}=0$

Multiple Choice

In comparing the difference of the means between two groups,the null hypothesis can also be stated as:

A) $\mu_{1}-\mu_{2}=0$
B) $\mu_{1}+\mu_{2}=0$
C) $\mu_{1} \mathrm{x} \mu_{2}=0$
D) $\mu_{1} / \mu_{2}=0$