Final answer:
The third phase of personnel management focused on corporate contribution and proactive management, including health and safety, equal opportunity programs, and security management.
Step-by-step explanation:
The third phase of personnel management was largely concerned with corporate contribution and proactive management. This phase went beyond the administrative and transactional functions like payroll and benefits administration to include more strategic elements such as compliance with health and safety legislation, the development of equal opportunity programs, and the implementation of comprehensive security management and safeguards. This evolution in the role of human resources reflects a shift towards viewing employees as strategic assets and recognizes the importance of fostering a safe, equitable, and well-managed workplace to enhance organizational performance.