You're right that the graph contains the data for both A and B (and for that matter C and D as well) but the question refers to what the slope means. Here we ha

You're right that the graph contains the data for both A and B (and for that matter C and D as well) but the question refers to what the slope means. Here we have a Y = MX + B graph. M indicates how much Y changes for every 1 unit change in X. So it's A.