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.
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. a greater proportion than it was ??? B. a greater proportion than C. a greater proportion than they have been D. which is greater than was so E. which is greater than it has been
我的理解是““a greater proportion”是“more than half the spending”的同位语,前面并没有省略“it is”。补全的话应该是“a greater proportion than the proportion in any previous election”.