If ‘k’ is coefficient of air resistance, ‘A’ is frontal area projected by the vehicle in square metres and ‘V’ is vehicle speed(in km/h) then the expession for air resistance ‘A.R’ on the vehicle is _________

• A. A.R = k*A*V^2
• B. A.R = k*A*V^3
• C. A.R = 2k*A*V
• D. A.R = k*A*V