Explanation

　　1.The correct answer is C

　　The error in this sentence occurs at (C), where there is subject-verb disagreement. The plural verb “make” does not agree with its singular subject, “An abundant supply.”

　　2.The correct answer is A

　　The error in this sentence is (A): the phrase "protest on" is not idiomatic in standard written English. The verb "protest" takes the preposition "against." The correct sentence reads: Originally a protest against conventional painting, the Pre-Raphaelite movement exerted great influence on the art of its time.

　　3.The correct answer is D

　　The error in this sentence occurs at (D), where there is an improper idiom. Both parts of the “both...and” structure must be followed by grammatically similar elements. Because “his” follows “both,” “his” must also follow “and” (“both his jazz and his classical”).

　　4.The correct answer is A

　　The error in this sentence occurs at (A), where there is an improper verb form. The use of “requires that” dictates that the subjunctive form of “to wear” is needed. The phrase “have been wearing” should simply be “wear.”

　　5.The correct answer is A

　　The error in this sentence occurs at (A), where there is an improper idiom. The phrase “in addition to” is needed in place of “also.”

　　6.The correct answer is D

　　The problem in this sentence is one of illogical comparison. Alexandra is said to consider Mohammed's insightful interpretation more sophisticated than the other performers, improperly comparing his interpretation to other performers, rather than to interpretations of other performers. The correct sentence reads: At the music recital, Alexandra enjoyed listening to her friend Mohammed's insightful interpretation, which she thought was more sophisticated than the interpretations of the other performers.