This is the definition of an interested party according to ISO 27001:2013, clause 3.16. An interested party is essentially a stakeholder, i.e., a person or organization that can influence or be influenced by the information security management system (ISMS) or its activities. Interested parties can have different needs and expectations regarding the ISMS, and these should be identified and addressed by the organization.
References:
* ISO/IEC 27001:2013, Information technology - Security techniques - Information security management systems - Requirements, clause 3.16
* PECB Candidate Handbook ISO 27001 Lead Auditor, page 10
* Identifying interested parties and their expectations for an ISO 27001 ISMS
* Examples of ISO 27001 interested parties

The three options of the corrections and corrective actions listed that you would expect ABC to make in response to the nonconformity are:
B . ABC cancels the service agreement with WeCare.
E . ABC introduces background checks on information security performance for all suppliers.
F . ABC periodically monitors compliance with all applicable legislation and contractual requirements involving third parties.
B . This option is a possible correction and corrective action that ABC could take to address the nonconformity. A correction is the action taken to eliminate a detected nonconformity, while a corrective action is the action taken to eliminate the cause of a nonconformity and to prevent its recurrence1. By cancelling the service agreement with WeCare, ABC could stop the unauthorized use of residents' personal data and protect their privacy and rights. This could also prevent further complaints and legal issues from the residents and their family members. However, this option may also have some drawbacks, such as the loss of a service provider, the need to find an alternative solution, and the potential impact on the residents' well-being.
E . This option is a possible corrective action that ABC could take to address the nonconformity. By introducing background checks on information security performance for all suppliers, ABC could ensure that they select and work with reliable and trustworthy partners who respect the confidentiality, integrity, and availability of the information they handle. This could also help ABC to comply with information security control A.15.1.1 (Information security policy for supplier relationships), which requires the organisation to agree and document information security requirements for mitigating the risks associated with supplier access to the organisation's assets2.
F . This option is a possible corrective action that ABC could take to address the nonconformity. By periodically monitoring compliance with all applicable legislation and contractual requirements involving third parties, ABC could verify that the suppliers are fulfilling their obligations and responsibilities regarding information security. This could also help ABC to comply with information security control A.18.1.1 (Identification of applicable legislation and contractual requirements), which requires the organisation to identify, document, and keep up to date the relevant legislative, regulatory, contractual, and other requirements to which the organisation is subject3.
Reference:
1: ISO 27000:2018 - Information technology - Security techniques - Information security management systems - Overview and vocabulary, clause 3.9 and 3.10 2: ISO/IEC 27001:2022 - Information technology - Security techniques - Information security management systems - Requirements, Annex A, control A.15.1.1 3: ISO/IEC 27001:2022 - Information technology - Security techniques - Information security management systems - Requirements, Annex A, control A.18.1.1

UpNet's certification was suspended because the certification body was not informed about the significant changes caused by the new department, impacting the governance of the management system. ISO/IEC 27001 requires organizations to inform the certification body of any changes that significantly impact the ISMS.

Management review is a crucial component of an ISMS that helps determine opportunities for continual improvement. Through management review, an organization assesses the performance and effectiveness of its ISMS, including reviewing opportunities for improvements and the need for changes to the ISMS, including the security policy and security objectives.
References: ISO/IEC 27001:2013 Standard, Clause 9.3 (Management Review)

According to the PECB Candidate Handbook for ISO/IEC 27001 Lead Auditor, the audit team leader should obtain information about the additional sites to inform the individual(s) managing the audit programme, as this may affect the audit objectives, scope, criteria, duration, resources, and risks. The audit team leader should also review the audit plan and make any necessary adjustments in consultation with the auditee and the audit client1. Reference: 1: PECB Candidate Handbook for ISO/IEC 27001 Lead Auditor, page 27, section 4.3.2.2.