Final answer:
A car moving left with constant velocity is not accelerating or decelerating. This is because acceleration involves a change in velocity, which includes both speed and direction.
Step-by-step explanation:
If a car is moving to the left with constant velocity, one can conclude that the car is not accelerating or decelerating. Acceleration refers to a change in velocity, which can be either a change in speed (magnitude) or direction. Since the car is moving with a constant velocity, neither the magnitude nor the direction of velocity is changing. Therefore, scenario 3 from the options given is correct - the car is not accelerating or decelerating.
To further clarify, recall that velocity is a vector quantity and it includes both speed and direction. If a car maintains a constant speed in a straight line, it is not accelerating. Acceleration would only occur if there was a change in speed or a change in direction, such as turning a corner.