Retailers reported moderate gains in their November sales, as much because of their sales of a year earlier being so bad as that shoppers were getting a head start on buying their holiday gifts.
Underlined: of their sales of a year earlier being so bad as that
Correct: their sales a year earlier had been so bad as because
I answered this question correctly, but only because I ruled out the other answer choices. I think this question is a parallel structure question, as indicated by 'as much because' and 'as because'. Is that right? And 'as because' sounds incorrect, but obviously, it's not. I'm not sure it makes sense to ask why 'as because' is not wrong, but any explanation might help.