WeeBee Company has three assembly labor dassifications: 5-1, S-2, and S-3. The three dassifications are paid $16, $19, and $22 per hour, respectively. The assembly activity for a product uses an S-2 employee who performs that task in 24 minutes. To reduce the activity cost per unit, a product engineer proposes using a low rated employee who can perform the assembly in 21 minutes. A manager proposes using a lower-rated employee who can perform the assembly in 30 minutes Which of the following provides the most cost-effective solution? a. use the S-2 employee b. use either the 5-1 or 5-3 employee Oc use the S-3 employee Od use the S-1 employee