Final answer:
The cornerstone liability insurance policy for a small business is a commercial general liability policy, offering broad protection against various claims related to business operations.
Step-by-step explanation:
The cornerstone liability insurance policy for a small business is a commercial general liability policy. This type of insurance provides broad coverage for a variety of liability claims, including bodily injury, property damage, and personal and advertising injury liability. It's designed to protect businesses against the risks they face in their day-to-day operations, ensuring that the business can endure financially in case of legal actions or claims of negligence.