Shelley gives her little sister a 5-meter head start in a bike race. The race ends 15 meters east from where Shelley started. If her little sister completes the race in 5 seconds, what is her sister’s average velocity? (Round your answer to the nearest whole number.)
A. 1 m/s east
B. 2 m/s east
C. 3 m/s east
D. 4 m/s east