The absence of a right-to-audit clause in the outsourcing contract for a cloud service provider would be of greatest concern to an IS auditor1. This clause gives the client the right to audit the service provider's activities that are relevant to the services being provided1. It is crucial for ensuring that the service provider is complying with the terms of the contract and meeting the client's standards for performance, security, and other aspects1. Without this clause, the client may not be able to effectively monitor and manage risks associated with the outsourcing arrangement1. References: * Audit rights in outsourcing: certifications and third party reports