A "direct variation" relationship has the form y = kx, where k is the "constant of proportionality.
Note that this graph goes thru the origin (which it must, to represent direct variation), and that it has a steep negative slope. That narrows down the answer choice to the first one: y = -2x.
So I looked at the graphs and the only one that actually even reaches 75 is the dotted one on the left. The one in the middle obviously doesn't go anywhere and the one on the right goes to 65, not 75.
