Task: Question Answering
Input (English): Background Paragraph: Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. 
Story: Jacob is an avid street car racer who is driving in his sleek black Mustang. He comes to a red light and sees the car next to him is an expensive looking Honda Civic, owned by a man named Alejandro. Jacob and Alejandro agree to race, and when the light turns green they both slam their feet on the gas pedal and take off. Jacob's car arrives at the light pole down the street from the light sooner than Alejandro's car, and he wins the race. 
Question: Which person's car, Jacob's or Alejandro's, must have accelerated slower?
Output (English): Alejandro's.