Final answer:
HRM is a function within organizations dealing with the management of people, while Organizational Behaviour is a field of study that explores social dynamics in the workplace.
Step-by-step explanation:
The statement that best describes the relationship between Human Resource Management (HRM) and Organizational Behaviour (OB) is: 'HRM is a function in organizations, organizational behavior is a field of study'. HRM pertains to the systematic approach to managing people within an organization, including recruitment, selection, training, and development. On the other hand, Organizational Behaviour is a wider field of study that looks at the impact that individuals, groups, and structures have on behaviour within organizations, for the purpose of applying such knowledge toward improving an organization's effectiveness.
Organizational psychology is the branch of study that delves deeper into the social interactions within a business setting and how they influence job satisfaction, management styles, leadership, organizational culture, and teamwork. Theories like Theory X and Theory Y highlight different managerial assumptions and practices, further illustrating the complexity of Organizational Behaviour.