Meagan is the manager of a factory. Workers at the factory are assigned to one of two tasks, one of which requires skilled labor and one of which requires unskilled labor. Because skilled workers earn a higher wage than unskilled workers, everyone who applies for a job says they're skilled. Meagan's challenge is to figure out who is actually a skilled worker and who is an unskilled worker. Suppose that Meagan would like to use the economic concept of screening to separate out worker types. Which of the following scenarios illustrates this concept? Meagan implements a test to determine whether applicants are skilled or not. Skilled workers pay to take a certification course to demonstrate their ability. Meagan voluntarily pays all workers a higher wage in hopes of attracting and retaining more productive workers