请教GWD10 的语法问题

handapink

请问为什么答案是C 不是E呢？

The results of the company’s cost- cutting measures are evident in its profits, which increased five percent during the first three months of this year after it fell over the last two years.
A. which increased five percent during the first three months of this year after it fell
B. which had increased five percent during the first three months of this year after it had fallen
C. which have increased five percent during the first three months of this year after falling
D. with a five percent increase during the first three months of this year after falling
E. with a five percent increase during the first three months of this year after having fallen

handapink

over the last two years

感觉这个前面应该用having fallen才对。。。为什么用falling 也可以呢....
with 从句仔细看了看也不好，因为after之前和之后的结构不对称，还是c好，除了那个falling不是很明白之外......