The correct answer would be - radiation curve graph.
Explanation:
The graph between air pressure with altitude would be a curve graph. The curve graph looks like one end at the x-axis and another end at the y-axis which indicates that if one variable increases then another variable would decrease accordingly.
It is due to the fact that air pressure decreases with the increase in elevation or altitude. So if the x-axis represents the change in air pressure and y-xis represents elevation it will look like a curve.
