Which of the following would most likely make a vehicle hard to steer?

A crimped power steering line can significantly impede the flow of power steering fluid, which is essential for the system's function. When the line is crimped, it creates a restriction that can lead to reduced hydraulic pressure and decreased assist provided by the power steering system. This means that the driver would need to exert more effort to turn the steering wheel, making it feel heavier and harder to steer the vehicle, particularly at low speeds or when maneuvering.

On the other hand, an overtightened power steering pump belt could lead to other issues, such as belt wear or pump damage, but it may not immediately cause difficulty in steering. Positive camber on the rear wheels typically helps with stability, and negative caster on the front generally impacts directional stability but may not directly make steering harder unless it is significantly out of specification.