For question 10, the answer lies in the wording "alternative explanation".... answer B might be a statement of fact about group dance, but it doesn't provide an explanation for how it could improve patient socialization. Option choice D does give an alternative explanation, based on increased desire to socialize.
For question 12, of the answer choices, only B connects a group activity with self-acceptance, so it is the only answer that is responsive to the question. I don't think that contradicts the info in the passage - you can feel you belong to a group without accepting others. The sense of belonging, feeling valued, could lead to self-acceptance, which then allows you to accept others.
Hope that helps!
Meaghan