23. please make answer clear

23. A car travels around a level circular track of radius r at a constant velocity. If the radius of the track is increased to or and the velocity of the car remains the same, which of the following represents the new centripetal force? (a) Six times the original centripetal force (b) Three times the original centripetal force (c) One-sixth the original centripetal force (d) One-third the original centripetal force