Colum

I think the idea here is to choose the BEST answer. Yes, the Treynor Ratio and Jensen's Alpha both use Beta and both basically tell you the same thing, which is a risk adjusted return. But the question is asking us which is most appropriate for evaluating "risk/return performance" So the measure we are looking for is a ratio of risk/return or return/risk. Jensen's Alpha is not a ratio, but the Treynor Ratio is. Treynor is giving us the return per unit of systematic risk. So because Treynor is a ratio, A is a BETTER answer than C.

As for answer B, I don't think we can assume there is no systematic risk despite the description of the fund as "well-diversified." I may be wrong, but I don't think we can ever formally say that ALL non-systematic risk has been diversified away...unless we are holding all securities in the market.