* Clause 8.2.4 of ISO 9001:2015 - Changes to Requirements for Products and Services:ISO 9001: 2015 Clause 8.2.4 states that when changes to requirements for products or services are made, they must be communicated and agreed upon with relevant interested parties (in this case, the Health Trust). The lack of communication and agreement for substituting the cleaning chemical represents a clear violation of this clause. * Analysis of the Corrective Action Proposed:The organization proposed "obtaining a concession from the Health Trust for the use of the new chemical." This action is reactive and assumes approval from the Health Trust without addressing the systemic issue: the lack of a defined change control process for managing contract changes. * Option Analysis: * A. The substitute chemical has not been used before in the Health Trust:Incorrect. While this may be a concern, it is not directly relevant to the root cause of the nonconformity, which is the absence of a process to handle contract changes. * B. The action assumes that the Health Trust will agree to the change:Incorrect. Although this is true, it is not the primary issue. The nonconformity lies in the lack of a structured approach to obtain agreement, not whether the Health Trust agrees. * C. Staff have not been trained in the use of the new chemical:Incorrect. This is a separate issue related to staff competence (Clause 7.2), but it is not the main reason why the corrective action is unacceptable under Clause 8.2.4. * D. The process for making changes to the contract has not been addressed:Correct. The fundamental issue is the organization's failure to follow or establish a change control process for amending contracts, including gaining formal agreement from the Health Trust. The proposed corrective action does not ensure that such issues will be systematically prevented in the future. * E. The substitute chemical may not be as effective as the original:Incorrect. The effectiveness of the substitute chemical is secondary to the primary issue, which is the lack of a change management process. * ISO 9001 References Supporting the Correct answer: * Clause 8.2.4: Requires that changes to product/service requirements be reviewed, communicated, and agreed upon with the customer. * Clause 10.2 (Nonconformity and Corrective Action): Requires the organization to address the root cause of the nonconformity and take actions to ensure it does not recur. In this case, the root cause is the absence of a change control process. * Why D is the Best answer:The core issue is that the organization did not have a formalized process for managing and agreeing upon changes to contract requirements. Addressing this process gap is essential to prevent recurrence of similar nonconformities. Merely seeking a concession from the Health Trust is a one-off solution that does not address the systemic issue.