can somebody explain why A is better than B?
I see one question from Kaplan 800
that might enlighten this issue:
Carthaginians are credited (with having salted) roman fields
Carthaginians are credited (with the salting of) roman fieldsKaplan
With having salted is less passive then "the salting of". So the first option is better.
Can we make the same association?
as extending vs as the extent?
It is not passivity here, which is making a difference in your example.
It is the idiom 'credited with'.
credited with is always associated with -ing form of verb. Apart from ur example:
Eg: Edison is credited with discovering of the bulb.
For this question, even I couldnt find a proper reason. If anyone can shed some light, it will be great.