use a noun or to do, pls,help

[thanghnvn]

The coyote is one of several recent ecological success stories: along with the white-tailed deer, the moose, and other species that are enlarging their natural domains,// they have established themselves as supreme adapters in an era when the capability// to adjust to the environmental changes wrought by human beings has created a whole new class of dominant large mammals.

A. they have established themselves as supreme adapters in an era when the capability
B. they have established themselves as being supreme adapters in an era when being able
C. it has established itself as a supreme adapter in an era when to be able
D. it has established itself as being a supreme adapter in an era when its ability
E. it has established itself as a supreme adapter in an era when the ability

pls, explain why C is wrong.

[nileshdalvimumbai]

Although it is not incorrect to have infinitive as a subject, inserting an infinitive as a subject introduces three "to's" in a row making the sentence awkward. Using a non-infinitive subject in such a case is a better and concise choice.

[tim]

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