Answer: A. direction and speed.
Velocity describes the speed of an object and the direction it's travelling in.
To describe the speed of something, you would say "That car is travelling 40 miles per hour."
To describe the velocity of something, you would say "That car is travelling 40 miles per hour North."
To better demonstrate, If a bus is traveling at 5 meters a second (m ⁄ s) and speeds up, its velocity has changed. If a bus is traveling at 5 m ⁄ s and turns right, while remaining at 5 m ⁄ s, its velocity has still changed.
