OG详解-OG7 文法 Q5

Choice C is the best answer. The convention being tested is the use of verb forms within a sentence. The nonfinite past participle “characterized” is correctly used within a supplementary element that modifies the main clause “Zhang...shanshui,” defining qinglü shanshui and explaining some of its identifying traits. 
Choice A is incorrect because it results in a comma splice. Using the finite present perfect tense verb “has been characterized” creates a second main clause in the sentence, and the two main clauses can’t be joined in this way by only the comma before “a type.” Choice B is incorrect because it results in a comma splice. Using the finite future tense verb “will be characterized” creates a second main clause in the sentence, and the two main clauses can’t be joined in this way by only the comma before “a type.” Choice D is incorrect because it results in a comma splice. Using the finite present tense verb “is characterized” creates a second main clause in the sentence, and the two main clauses can’t be joined in this way by only the comma before “a type.”