<p>It's B because it's a comparison. A, C, and D don't provide a word of comparison. E I assume you can figure out what's wrong with. It complemented it more than it replaced it; it's a comparison. </p>
<p>It's confusing because they don't have two optional words. "as much as complement" would be the way I would have written it, but the "as much" is redundant with "so much." I would have excluded "so much" and said "Early American factories did not replace household manufacturing as much as complement it." But nonetheless, B is still correct.</p>