He had always had a good opinion of himself, but after the publication of his best-selling novel he became unbearably______.

【正确答案】 C

【答案解析】解析：句意：他本来就很自以为是，但自从他发表了自己的畅销小说后，他自负得令人难以忍受。conceited自负的，自大的。cordial热忱的，兴奋的。proud自豪的，得意的。exaggerated夸大的，夸张的。