【单选题】The author’s claim that, since the mid-1970’s, a new strategy has emerged in the unionization of public-sector clerical workers (line 23 ) would be strengthened if the author______
A.
described more fully the attitudes of clerical workers toward labor unions
B.
compared the organizing strategies employed by private-sector unions with those of public-sector unions
C.
explained why politicians and administrators sometimes oppose unionization of clerical workers
D.
indicated that the number of unionized public-sector clerical workers was increasing even before the mid-1970’s
E.
showed that the factors that favored unionization drives among these workers prior to 1975 have decreased in importance