What Is the H₀ for Testing Differences of the Means

Multiple Choice

What is the H₀ for testing differences of the means of two independent samples?

A) $\mathrm { H } _ { 0 } : \mu _ { 1 } - \mu _ { 2 } = 0$
B) $\mathrm { H } _ { 0 } : \mu _ { 1 } \neq \mu _ { 2 }$
C) $\mathrm { H } _ { 0 } : \mu _ { 1 } > \mu _ { 2 }$
D) $\mathrm { H } _ { 0 } : \mu _ { 1 } < \mu _ { 2 }$