What type of payment is an example of operational phase financing?

The correct choice, which is an availability payment, serves as a clear example of operational phase financing because it is directly tied to the operational performance of an asset. Availability payments are typically made by a public authority or client to a private party under a public-private partnership (PPP) arrangement. These payments are contingent upon the asset being available and operational according to specified performance standards, emphasizing the operational aspect of the financing. Essentially, this type of payment aligns the financial incentives of the private partner with the successful delivery of services.

Other types of payments mentioned do not align closely with the operational aspect. For instance, fixed price payments may relate more to initial project costs or contract pricing rather than ongoing operational performance. Cost of capital refers to the amount of money required to finance the project's initial investment; it does not pertain to ongoing operational financing. Expense payments typically cover regular operational costs but might not be structured in a way that links payment to specific performance metrics, making them less representative of operational phase financing compared to availability payments.