A and C are both correct to a degree. He is well known for his peculiar geometric forms in his paintings, which were not at all realism, but rather a style called cubism. During his Blue Period, his paintings were literally painted in blues, and were true to the answer in C. One particular painting depicts an elderly man playing a guitar with a frown on his face looking incredibly sad and upset. I would probably select C because it describes his Blue Period in contrast to his typical style, which is described in A.
The correct answer is (D)
He wishes he could thank the young boys who taught him to read.
