Round to the Nearest Tenth Unless Indicated Otherwise $40 \mathrm { mph }$

Multiple Choice

Round to the nearest tenth unless indicated otherwise.
-Wind resistance or atmospheric drag tends to slow down moving objects. Atmospheric drag varies jointly as an object's surface area A and velocity v. If a car traveling at a speed of $40 \mathrm { mph }$ with a surface area of $34 \mathrm { ft } ^ { 2 }$ experiences a drag of $231.2 \mathrm {~N}$ (Newtons) , how fast must a car with $39 \mathrm { ft } ^ { 2 }$ of surface area travel in order to experience a drag force of $483.99 \mathrm {~N}$ ?

A) 75 mph
B) 78 mph
C) 70 mph
D) 73 mph