"Portfolio Management":Treynor ratio and Jensen’s alpha

B is correct. For an investor who holds a fully diversified portfolio, the Treynor ratio and Jensen’s alpha are the appropriate portfolio performance measures. They are appropriate because in a fully diversified portfolio, only systematic risk matters; both these metrics measure performance relative to beta or systematic risk. 

A is incorrect. The Treynor ratio is appropriate for an investor who holds a fully diversified portfolio, but the Sharpe ratio is appropriate for an investor who does not hold a fully diversified portfolio.

 C is incorrect because these measures are appropriate for an investor who does not hold a fully diversified portfolio.

A is correct. Tax risk, the risk that the tax code could change, along with regulatory and accounting risks together form compliance risk. Legal risk is the risk of being sued or the risk that a court will not uphold an agreement. Model risk is the risk of using the wrong model for analysis or the risk of using the right model incorrectly.

B is incorrect because model risk is the risk of using the wrong model for analysis or the risk of using the right model incorrectly. 

C is incorrect because legal risk is the risk of being sued or the risk that a court will not uphold an agreement.