In which situation is the insured liable for the acts of an independent contractor?

The insured may be liable for the acts of an independent contractor under specific circumstances that can indicate a degree of control or involvement in the contractor's work. One key aspect of liability is the level of control the insured asserts over the contractor's work.

When the insured hires and fires employees of the contractor, this indicates a significant level of control over the contractor's operations, suggesting that the insured has a role in determining how work is performed. This control can lead to liability because it may blur the lines between independent contractor and employer.

Providing tools and materials that the contractor uses can also result in liability. When the insured supplies the means to carry out a task, they may be considered to have a hand in how that work is performed, potentially exposing them to liability for the contractor's actions.

On-site direction and supervision significantly increase the likelihood of liability as this indicates that the insured is not merely hiring out the work but also influencing the manner in which it is executed. If the insured is directing how the work is to be done, they assume a greater level of responsibility.

Given these conditions, all of the stated situations can lead to liability for the insured regarding the actions of an independent contractor, hence the correct answer encompasses all these factors.