The following describes different types of services that CPAs can offer customers. Highlight the description that best adheres to previously agreed services (agreed-upon procedures).

a. The nephew pays for a CPA firm to analyze his aging uncle's finances before he can be accepted into a foster home.

b. None of the other alternatives

c. A certain company that processes payroll for other clients wants to have a report that provides assurance that its internal control system is adequate, so that the external auditors of the clients that this company serves can take it into consideration.

d. A bank hires a CPA firm to confirm a prospective customer's accounts receivable, which offers its accounts receivable as collateral for a loan.