GMATPrep -- Prepositional phrase as modifier

[GMATMadeEasy]

Even though it was not illegal for the bank to share its customers' personal and financial information with an outside marketing company in return for a commission on sales, the state's attorney general accused the bank of engaging in deceptive business practices by failing to honor its promise to its customers to keep records private.

(A) by failing to honor its promise to its customers to keep
(B) by its failure of honoring its promise to its customers to keep
(C) in its failing to honor its promise to its customers of keeping
(D) because of its failure in honoring its promise to its customers in keeping
(E) because of its failure to honor its promise to its customers of keeping

OA is A .

I am really wondering how to deal and interpret these phrases with respect to attorney and/or banks. Help please. I understand idiom errors in all the answer choices though.

A struggling GMAT warrior .

[Tani]

The bank is accused of two things: "engaging" and "failing". Those verb forms need to be parallel.

[GMATMadeEasy]

@Tani Wolff - Kaplan

The bank is accused of two things: "engaging" and "failing". Those verb forms need to be parallel.

How do you get to that ?

Bank is NOT accused of two things. Bank is accused of SOMETHING (deceptive business pratices) because it did something .
Furthermore, had there been two verbs, author would have needed a parallel marker. There is none here . Could you clarify .

[champmag]

The state attorney accused the bank of 'engaging' in X. Now how did this enagaging X happen?

By 'failing' in Y. Thus the two constructions need to be parallel.

Accused the bank of engaging in X by failing in Y.

C is unidiomatic. Only A fits the bill.

[ankurmit]

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