An Airplane Flies from Point a to Point B,a Distance

Multiple Choice

An airplane flies from point A to point B,a distance of 100 km,and back again with an airspeed of 250 km/h.What is the difference in the time for this round trip on a day when a wind of speed 50.0 km/h blows from A toward B and on a day when a wind of speed 50.0 km/h blows in a direction perpendicular to AB?

A) zero
B) 1.0 min
C) 5.5 min
D) 4.5 min
E) 10 min