Two investment advisors, Mrs A and Mr C, are comparing performance. Mrs A's portfolio has averaged 17.5% over the past 5 years, Mr C's only 10.5%. Over the same period, the average return on a market benchmark portfolio was 12%. a a) Without further information, can you say who was the better asset manager? b) You analyse the data more carefully, and estimate that A's portfolio had a beta of 1.6 relative to the market benchmark, while C's beta was 0.8. Over the period in question, the average T-bill return was 2%. How does your answer to a) change? c) How would your answer change if the T-bill rate had been 6%