GMAT Sentence Correction (SC) | Re: Even though it was not illegal for the bank to share its

mmm.... don't go applying parallelism blindly :

.... Failure to ...
honor is promise to......

These are at two separate levels and hence don't need parallelism.

Also this is plain wrong because the sentence can be interpreted in the following way :

deceptive business practices because of its failure to honor

So the bank engaged
...

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