What must an insurer have in order to provide coverage for a risk?

An insurer must have a base of homogeneous risks to effectively provide coverage for a risk. Homogeneous risks refer to a group of risks that are similar in nature and are expected to have similar loss characteristics. This similarity allows insurers to reliably assess the likelihood of claims and set premiums accordingly.

By grouping similar risks, insurers can utilize statistical methods to predict future losses and ensure that they have sufficient funds to cover claims. This is essential for the sustainability of an insurance business, as it enables underwriting practices that maintain a balance between received premiums and potential payouts.

In contrast to this, the other options do not directly relate to the fundamental principle of risk pooling and management in insurance. The requirement of specific financial measurements or a broad understanding of liabilities may be important, but they do not encapsulate the core necessity that insurers need to manage and effectively underwrite risks. Inherent security features could also be relevant in certain contexts but do not fundamentally define the groundwork for risk coverage in insurance.