A large and increasingly influential sector of publishing, 20 percent of all the National and American Book awards since 1950 have gone to university-press books.
(A) A large and increasingly influential sector of publishing, 20 percent of all the National and American Book awards since 1950 have gone to university-press books.
Incorrect: "A large and increasingly influential sector of publishing" is modifying "university-press books," so "university-press books" should come directly after the comma
(B) A large and increasingly influential sector of publishing, university-press books have won 20 percent of all the National and American Book awards since 1950.
Correct: "university-press books comes after the clause that modifies it. Also "have won" is the correct tense to use since it is talking about an event "since 1950" (not sure if this is necessary, but I thought I'd throw that out there)
(C) Increasingly influential as a large sector of publishing, 20 percent of all the National and American Book awards since 1950 have gone to university-press books.
Incorrect: Same problem as in choice A.
(D) Since 1950, a large and increasingly influential sector of publishing, 20 percent of all the National and American Book awards have gone to university-press books.
Incorrect: Award phrasing
(E) Since 1950, university-press books, a large and increasingly influential sector of publishing, won 20 percent of all the National and American Book awards from then on.
Incorrect: Seems like awkward phrasing. Also, i'm not 100% sure, but is the tense on the verb "won" incorrect? Should it be "have won" or does it not matter?