According to Kantian ethics, company X should not use engineer A$’$s proposed code, because

$1$ point

the effect of this code is inconsistent with the reading of the NSPE Code of Ethics.

this is a maxim that I can will to become a universal law, since if everyone does not use deceitful code, this would lead to a world where codes can be trusted and continue to be meaningful.

the code would be inconsistent with the obligation to public health and safety.

the code would lead to unacceptable pollution.