As described in the passage, Porter’s method of criticizing art can best be summarized by which of the following statements?
A. Porter’s criticisms were frank and forthright, and were based solely on his evaluation of the piece of art that he was appraising.
B. Porter criticized art based on the context of the painting and conceptual structures that he found most useful in his evaluations.
C. Porter’s critiques were comparable to those of Bernard Berenson, who greatly influenced Porter’s outlook on art.
D. Porter targeted his criticisms at helping artists by attempting to influence their forthcoming works.