The correct answer is B

Explanation

Choice (B) is correct. If this term were inserted into the sentence, the sentence would read “Mr. Warmington considered himself a connoisseur of fine wines, claiming he could discern variations in taste and quality among any range of vintages he was served.” A “connoisseur” has a sophisticated ability to appreciate and assess subtleties. If Mr. Warmington considered himself a connoisseur of wine, he would claim an ability to “discern,” or detect, variations in the taste and quality of different wines.