A Student in the Front of a School Bus Tosses

A student in the front of a school bus tosses a ball to another student in the back of the bus while the bus is moving forward at constant velocity. The speed of the ball as seen by a stationary observer in the street:

A) is less than that observed inside the bus.
B) is the same as that observed inside the bus.
C) is greater than that observed inside the bus.
D) may be either greater or smaller than that observed inside the bus.
E) may be either greater, smaller, or equal to that observed inside the bus.