Answer:
Portfolio A is preferred.
Explanation:
Given the following sorted data from the question:
Fund     Avg     Std Dev     Beta
A Â Â Â Â Â Â Â Â 17.5% Â Â Â Â 26.5% Â Â Â Â 1.35
B Â Â Â Â Â Â Â Â 12.5% Â Â Â 23.5% Â Â Â Â Â 1.10
C Â Â Â Â Â Â Â Â 13.5% Â Â Â 20.5% Â Â Â Â Â 1.15
S&P 500 Â Â 10% Â Â Â Â Â 15% Â Â Â Â Â Â Â 1
rf          4.0%
To determine the preferred portfolio, the Treynor measure for each portfolio is estimated as follows:
Treynor measure = (Avg - rf rate) / beta
Therefore, we have:
Treynor measure of Portfolio A = (17.5% - 4.0%) / 1.35 = 10.00%
Treynor measure of Portfolio B = (12.5% - 4.0%) / 1.10 = 7.73%
Treynor measure of Porfolio C = (13.5% - 4.0%) / 1.15 = 8.26%
Since the 10% Treynor measure of Portfolio A is the highest, Portfolio A is preferred.