A study by the Hermann commission urged SEB to undertake a series of measures to arrest the gradual decrease in the number of listed .com firms, which includes the establishment of lower limits for annual revenues, and scaling down such other norms selectively for small technology and internet firms.
A. which includes the establishment of lower limits for annual revenues, and scaling
B. which includes establishing limits to the size of annual revenues, and scaling
C. which include the establishment of lower limits for annual revenues, and the scaling
D. including establishing lower limits for annual revenues, and scaling
E. including the establishing of limits to the size of annual revenues, and the scaling
firms,which .....which refers to firms hence plural
A and B out S-V agreement error
E is awkward and nonsensical
In C and D
here comes the parallelism into picture
In C
establishment is noun and scaling down (action)
So
D is the best answer
establishing lower limits and scaling down (both denotes some action)