A Researcher Believes Exercise Reduces Anxiety in Women $\mu$ ₁ $\not=$ $\mu$

A researcher believes exercise reduces anxiety in women. She identifies a group of women who had not exercised before but are now planning to begin exercising. She gives them a 50-item anxiety inventory before they begin exercising and administers it again after six months of exercising. The anxiety inventory is measured on an interval scale and higher numbers indicate higher anxiety. In addition, scores on the inventory are normally distributed. The scores are given below.


-The alternative hypothesis for a two-tailed independent-groups t test states that:

A) H₀: $\mu$ ₁ $\not=$$\mu$ ₂.
B) H₀: $\mu$ ₁ = $\mu$ ₂.
C) H_a: $\mu$ ₁ $\not=$$\mu$ ₂.
D) H_a: $\mu$ ₁ = $\mu$ ₂.