Simplify the following expression:

So we'd solve this like;

$$2x-8y+3x^2+7y-12x$$  ( now we will place the like terms together)

$$=2x-12x-8y+7y+3x^2$$  (now we'll simply solve them)

$$=-10x-y-3x^2$$  (now we'll place them in a proper order)

$$=3x^2-10x-y$$  $$ANSWER$$

So your ANSWER IS THE second option!

Hope this helps!