OG详解-OG7 文法 Q20

Choice C is the best answer. The convention being tested is the punctuation of elements in a complex series. It’s conventional to use a semicolon to separate items in a complex series with internal punctuation, and in this choice, the semicolon after “items” is conventionally used to separate the first item (“overseeing…items”) and the second item (“managing…law”) in a list of Hayden’s responsibilities. 
Choice A is incorrect because it fails to use appropriate punctuation to separate the first item and the second item in the complex series. Choice B is incorrect because a comma after “items” doesn’t match the semicolon used later to separate the second and third items in the series (“managing…law” and “and appointing the US poet laureate”). Choice D is incorrect because it results in a rhetorically unacceptable sentence fragment beginning with “Managing.”