Final answer:
Theory W is not a popular management theory, while Theory X and Theory Y are recognized concepts that describe contrasting workforce motivations; Situational Leadership is also a well-known management style that varies based on the situation.
Step-by-step explanation:
The management theory that is not currently popular among the choices given is Theory W. Theory X and Theory Y are well-known theories developed by Douglas McGregor that describe two contrasting models of workforce motivation. Theory X assumes that employees inherently dislike work and must be coerced, controlled, and threatened with punishment to achieve goals, while Theory Y posits that employees are naturally self-motivated and thrive on responsibility. Additionally, Situational Leadership is a management model that suggests that no single leadership style is the best. Instead, it depends on the situation, including the level of maturity of the followers, the task, and other situational factors. Theory W does not align with established management theories and is not recognized as a popular management concept in current organizational studies.