Caster is the angle of the steering axis from the vertical when viewed from the side. A positive caster enhances straight-line stability but requires more steering effort. Conversely, negative caster lessens the steering effort. This is why vehicles intended for easy low-speed maneuvering, like older or lighter cars, often feature slight negative caster. However, excessive negative caster can compromise directional stability at higher speeds. Toe-in and positive camber primarily impact tire wear and vehicle handling, not directly steering effort. Consequently, the correct response is Negative caster.