A car starts from rest and accelerates down a slope. The acceleration remains constant as the car travels from the top to the bottom of the slope. The average speed of the car is 2 m/s. The speed of the car as it reaches the bottom of the slope is: A. 0 m/s B. Between 0 m/s and 2 m/s C. 2 m/s D. Between 2 m/s and 4 m/s E. 4 m/s F. Greater than 4 m/s

This seems like homework so I'll give some hints. 

- Some values may be trivially incorrect, which ones can you eliminate?
- Are you familiar with any equations that could be used? Acceleration is known to be constant and initial velocity is zero (car starts from rest)