Answer:
Option B is the correct answer.
Explanation:
Velocity of a body = Displacement of the body/Time taken
Displacement and velocity are a vector. Both have direction and magnitude.
Displacement is generally distance with direction.
If we divide distance with time taken we will get speed of the airplane. Speed with direction is called velocity. So we need distance between Houston and Dallas, time taken by plane to travel from Houston to Dallas and direction of displacement from Houston to Dallas.
So we need direction.
Option B is the correct answer.