The aspects of staffing do not include:

Option 1 -> Training is a key aspect of staffing that involves developing employees' skills and competencies for their roles.

Option 2 -> Selection is a core staffing function that involves choosing the right candidates from the pool of applicants.

Option 3 -> Assignment of work is part of the directing/leading function of management, not the staffing function.

Option 4 -> Recruitment is a fundamental staffing activity that involves attracting and searching for potential candidates.

Hence, Option 3: Assignment of work -> Assignment of work falls under the directing or organizing function of management, where managers allocate tasks and responsibilities to employees. Staffing focuses on acquiring, developing, and maintaining human resources (recruitment, selection, training, promotion, compensation), while work assignment deals with operational management of existing staff -> correct