What type of insurance would typically amend a standard homeowner's policy to include protection against earthquakes?

The correct choice is an endorsement because an endorsement is a modification or addition to a standard insurance policy that provides coverage for specific risks that the base policy does not include. In the context of homeowner's insurance, a standard policy typically covers various perils such as fire, theft, and wind damage but often excludes coverage for earthquakes. By adding an endorsement to the homeowner's insurance policy, the homeowner can extend their coverage to include damages caused specifically by earthquakes.

Liability insurance generally covers legal claims for bodily injury or property damage caused by the policyholder, but it does not extend to specific perils like earthquakes. An umbrella policy provides additional liability coverage above the limits of existing policies, and serves a different purpose rather than directly modifying a homeowner's coverage. Replacement value insurance refers to a method of determining the value of insured property, ensuring it is replaced at current market costs, and does not specifically address the inclusion of additional perils like earthquakes in a homeowner's policy.