Which of the following is typically included in a comprehensive policy as an optional extension?

A comprehensive insurance policy often encompasses a variety of coverage options, and among these, breakage of glass is commonly included as an optional extension. This is because glass damage, such as a cracked windshield, is frequent and can be costly to repair. By offering this as an optional extension, insurers allow policyholders the flexibility to enhance their coverage based on their specific needs or preferences.

Coverage for accidental damage to the vehicle and liability for passenger injuries are typically fundamental components of most vehicle insurance policies rather than optional extensions. Coverage for racing events, while often deemed a specialized or high-risk activity, is usually excluded from standard comprehensive policies, as standard policies are not designed to cover vehicles used in racing scenarios. Thus, breakage of glass stands out as a relevant option that can be added to enhance comprehensive insurance coverage.