To begin this question, I would put the given equation into slope-intercept form (y = mx + b), which would be By = -Ax + 12. After this, I can divide both sides by B to get y = -A/Bx + 12/B. Looking at the graph, I can see that the y-intercept of the equation is 6, so I now know that B must be 2 because 12 represents the y-intercept, and since it is being divided by B, B must be 2 to equal 6. So now I have y = -A/2x + 6, and again just by looking at the graph I can see that the slope is -3/2, meaning that A must equal 3 for the equation to match the graph. 3 is the correct answer.