Comprehensive and Detailed Explanation:
Corrective controls are measures taken to restore systems or processes after an incident or error has occurred.
Option C: Rollback scripts and backup procedures restore systems, making them corrective controls.
Option A: Separation of duties and hash totals are preventive controls.
Option B: Audit reviews are detective, while remediation may include corrective, but audits themselves aren't corrective.
Option D: Disciplinary actions are deterrent controls.
# ISACA Reference: CISA Review Manual 27th Edition, Domain 4, section on types of IT controls (preventive, detective, corrective, deterrent).

The most important thing to include in security awareness training is how to respond to various types of suspicious activity. Security awareness training is a program that educates employees about the importance of security and how to avoid common threats and risks. One of the main objectives of security awareness training is to enable employees to recognize and report any signs of malicious or unauthorized activity, such as phishing emails, malware infections, data breaches, or social engineering attempts. By teaching employees how to respond to various types of suspicious activity, security awareness training can help to prevent or mitigate the impact of security incidents, protect the organization's assets and reputation, and comply with legal and regulatory requirements.
The other options are not as important as option A. The importance of complex passwords is a useful topic, but not the most important thing to include in security awareness training. Complex passwords are passwords that are hard to guess or crack by using a combination of letters, numbers, symbols, and cases. Complex passwords can help to protect user accounts and data from unauthorized access, but they are not sufficient to prevent all types of security incidents. Moreover, complex passwords may be difficult to remember or manage by users, and may require additional measures such as password managers or multi-factor authentication.
Descriptions of the organization's security infrastructure is a technical topic, but not the most important thing to include in security awareness training. Security infrastructure is the set of hardware, software, policies, and procedures that provide the foundation for the organization's security posture and capabilities. Security infrastructure may include firewalls, antivirus software, encryption tools, access control systems, backup systems, etc. Descriptions of the organization's security infrastructure may be relevant for some employees who are involved in security operations or administration, but they may not be necessary or understandable for all employees who need security awareness training. Contact information for the organization's security team is a practical detail, but not the most important thing to include in security awareness training. Security team is the group of people who are responsible for planning, implementing, monitoring, and improving the organization's security strategy and activities. Contact information for the organization's security team may be useful for employees who need to report or escalate a security issue or request a security service or support.
However, contact information for the organization's security team is not enough to ensure that employees know how to respond to various types of suspicious activity. References: Security Awareness Training | SANS Security Awareness, Security AwarenessTraining | KnowBe4, SecurityAwareness Training Course (ISC)² | Coursera

Following a breach, the maximum amount of time before customers must be notified that their personal information may have been compromised depends on the industry regulations that apply to the organization.
Different industries and jurisdictions may have different legal and regulatory requirements for breach notification, such as the General Data Protection Regulation (GDPR) in the European Union, the Health Insurance Portability and Accountability Act (HIPAA) in the United States, or the Personal Information Protection and Electronic Documents Act (PIPEDA) in Canada. Industry standards, incident response plans, and information security policies are not as authoritative as industry regulations in determining the breach notification time frame. References: CISA Review Manual (Digital Version), [ISACA Privacy Principles and Program Management Guide]

The greatest risk to an organization's ability to manage QC processes is the lack of policies and procedures that define the QC objectives, standards, methods, roles, and responsibilities. Without policies and procedures, the QC processes may be inconsistent, ineffective, inefficient, or noncompliant with the relevant regulations and best practices. Policies and procedures provide the foundation and guidance for the QC processes and help to ensure their quality, reliability, and accountability.
References
ISACA CISA Review Manual, 27th Edition, page 253
Quality Control - an overview | ScienceDirect Topics
Quality Control: Meaning, Importance, Definition and Objectives