The conclusion of separation theory is that: A) the determination of the best CAL is objective, and the choice of the inputs to be used to determine the efficient frontier is subjective. B) the choice...

The conclusion of separation theory is that:

A) the determination of the best CAL is objective, and the choice of the inputs to be used to determine the efficient frontier is subjective.
         B)   the choice of the best complete portfolio is objective, and the determination of the best risky portfolio is objective.
         C)   the choice of inputs to be used to determine the efficient frontier is objective, and the choice of the best CAL is subjective.
         D)   the choice of the best complete portfolio is subjective, the determination of the best risky portfolio is objective.

         E)   investors are separate beings and will, therefore, have different preferences regarding the risk-return tradeoff.

Please provide justification