If We Are Interested in Testing Whether the Mean of Items

If we are interested in testing whether the mean of items in population 1 is significantly smaller than the mean of items in population 2, the

A) null hypothesis should state $\mu$ ₁- $\mu$ ₂ < 0
B) null hypothesis should state P₁ - P₂ $\ge$ 0
C) alternative hypothesis should state P₁ - P₂ > 0
D) alternative hypothesis should state $\mu$ ₁- $\mu$ ₂ < 0