The Problem, in Principle, with Evaluating the Overall IMC Program

The problem, in principle, with evaluating the overall IMC program based on the sum of each individual element is that

A) it can't be done.
B) no attempt is made to measure the synergy of a IMC campaign.
C) each media is evaluated with a different standard and the lack of a common standard means no total, overall summary score can be computed.
D) it's not worth the effort since few firms practice an IMC approach.