Which statement is true regarding aeroplane flight at L/Dmax?
a. Any angle of attack other than that for L/Dmax increases parasite drag.
b. Any angle of attack other than that for L/Dmax increases the lift/drag ratio.
c. Any angle of attack other than that for L/Dmax increases total drag for a given aeroplane's lift.
d. Any angle of attack other than that for L/Dmax increases the lift and reduces the drag