The Watson Family is going on a road trip. The data in the table shows the relationship between speed and fuel economy for their car. The data can be modeled by the quadratic function y=-0.0075x^2 +0.575x + 11.5, where x represents the speed in miles per hour and y represents the fuel economy in miles per gallon (MPG). Which speed rounded to the nearest whole number will give them the best fuel economy? A. 40 mph

B. 23 mph

C. 32 mph

D. 38 mph

It keeps saying image is to big so I'll type
Table:
Speed (miles per hour)
30
40
50
Fuel economy (miles per gallon)
22.0
22.5
21.5