one Sat writing question, Someone help me thanks

<p>Fabric was very expensive in the US before the Industrial (Revolution, this is why )scraps were saved and recycled into such items as patchwork quilts and doll clothes.</p>

<p>C revolution. and so
D Revolution and so that</p>

<p>I chose D because I think it was cause and effect. Besides, " and so" is not even gramattical correct? but the answer is C why?</p>

<p>C
as u said, it’s a cause n effect relationship, so we need " so "
" and so " = so, and it’s grammatically correct; before " so " and " yet " , " and " can be placed.
D is wrong because " so that " shows a purpose not cause n effect relationship + " and so that " isn’t grammatically correct.</p>

<p>“And so” came up a few months ago, so I looked it up. At first glance, it seems incorrect, because it looks like two conjunctions in a row. It is not. In this construction, “so” is an adverb. It means something like “thus” or “this being the case.” It is correct and commonly used in all levels of writing.</p>

<p>In the construction “so that,” however, “so” is used as a conjunction. Since “so” cannot be used as a conjunction AND an adverb at the same time, D is incorrect.</p>