Which BOP endorsement must Madelyn purchase for coverage of business income loss due to utility service interruption?

The endorsement that Madelyn must purchase to cover business income loss resulting from utility service interruption is known as the Utility Services - Time Element endorsement. This coverage is specifically designed to protect against losses that occur when a business cannot operate due to the interruption of essential utility services such as electricity, water, or gas.

When a utility service is disrupted, it can lead to significant financial losses due to halted operations, including lost income and ongoing expenses that still need to be covered. The Utility Services - Time Element endorsement provides compensation for these kinds of income losses while the business is unable to function.

The other options do not provide coverage for business income loss due to utility service interruptions specifically, which is why they do not fit this particular need. The Protective Safeguards endorsement relates to loss prevention measures rather than income loss. Hired and Non-owned Auto Liability covers liability for vehicles not owned by the business. The Utility Services - Direct Damage endorsement focuses on physical damage to the property caused by utility interruptions, rather than the income loss incurred during the interruption. Therefore, the Utility Services - Time Element endorsement is the appropriate choice for Madelyn's situation.