<em>∙•❁</em>Okay so we are going to solve for c so lets begin.<em>❁•∙ </em>

<em>∙•❁</em>We are going to divide both sides by 4.

<em>∙•❁</em>Your Final answer is:

<em>∙•❁I hope this helps!❁•∙ </em>
So k=1000 like 4k=4 000 so 6/7 of a thousnad =0.857142857 so times 6=0.857142857
I’m guessing A? Sorry if it’s wrong!