GMAT Sentence Correction (SC) | Re: Corporate finance committees do not plan the detailed

I see A have a problem

main clause+by+noun

in this pattern, by allocation is unclear. who allocation. we do not have this pattern in english.

I learn english by speaking it all day
speaking refers to I , but
i learn english by speaking of english

is wrong,
speaking here word ad pure noun and refer to no agent in the sentence. this case is similar to our offical answer A

am I correct?

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