In this scenario, the car is moving with a uniform speed, meaning that its magnitude of velocity remains constant. However, the momentum of the car is changing, indicating that there is a change in the car`s mass, velocity, or both.

Option 1 suggests that the car may be on an elliptical path. An elliptical path consists of two foci, and the car moving on such a path would constantly change its direction and velocity. This option does not align with the fact that the car is moving with uniform speed, so it can be ruled out.

Option 2 states that the car is moving on a straight path without acceleration. If there is no acceleration, it means that there is no change in velocity, and momentum should remain constant. However, since the car`s momentum is changing, option 2 is incorrect.

Option 3 suggests that the car is moving on a straight path with acceleration. This option could be valid since acceleration can cause a change in momentum, even when the speed remains constant. Therefore, option 3 is a plausible answer.

Option 4 claims that the car is moving without any acceleration. This contradicts the statement that the car`s momentum is changing. Hence, option 4 can be eliminated.

In conclusion, option