Solve the Problem $x$ , and Heating Oil $y$ , in Thousands of Gallons Per Week Is

Solve the problem.
-An oil refinery can produce gasoline, heating oil, or a combination of the two. The product exchange function for gasoline, $x$ , and heating oil, $y$ , in thousands of gallons per week is:
$$y=\frac{72,000-8 x}{36+2 x}$$
By sketching the quadrant I portion of the graph of this function, estimate the maximum quantity of each product that can be produced per week.

A) gasoline: $9,000,000$ gal; heating oil: $2,000,000$ gal
B) gasoline: 2,000,000 gal; heating oil: $9,000,000$ gal
C) gasoline: 4,500,000 gal; heating oil: 1,000,000 gal
D) gasoline: 9000 gal; heating oil: 2000 gal