The correct answer is: Theory X

Rationale: Theory X is the managerial assumption that most people dislike work and responsibility and will avoid them if possible they have to be coerced and controlled to work adequately - hence the kinds of management measures described.

Theory Y is the managerial assumption that people can be motivated to accept challenge and responsibility and contribute willingly to the firm - resulting in a quite different management style! You should have known that there are no theories W or Z!

Pitfalls: You really do need to know which way round X and Y are! (If it helps, think of X as a 'cross' against workers' names.)