When the moving soccer ball strikes the stationary one, the force exerted by the moving ball will cause the stationary ball to start moving. The momentum from the moving ball will transfer to the stationary ball, causing it to move in the same direction as the first ball. Additionally, the moving ball will lose some of its speed due to the collision.
Considering this information, the correct response is:
The stationary soccer ball will begin moving downfield and the ball that struck it will slow down.