请教GWD-1-16语法题-->携隐转移

Fabulous

Q16:

Soaring television costs accounted for more than half the spending in the presidential campaign of 1992, a greater proportion than it was in any previous election.

a greater proportion than it was

a greater proportion than

a greater proportion than they have been

which is greater than was so

which is greater than it has been

答案是C, 为什么

lilyzy

答案是B.