Is Part A as simple as accepting the individual projects with an expected return greater than 15%?

For Part B, would you use the Expected Stock Return formula and accept projects greater than 15%? For example, project #1, r = 8 + 0.5(7) = 11.5%, so do not accept this project? For project #2, 8+0.8(7) = 13.6, don't accept?

Question 8.1 makes no sense to me.  Aren't we suppose to treat each project as mini-firms and evaluate them based on their own OCC (Section 10.1 3rd paragraph 9th ed)?  Betas of projects 1-4 suggest that they have a different risk from the company's existing business (company beta is 1), so the company's hurdle rate of 15% should not be used to evaluate each project.  I think ultimately the criterion should be on which project gives the highest NPV based on its own OCC and cash flow.

Or is there something that I'm missing from the question?