WeeBee Company has three assembly labor classifications: S-1, S-2, and S-3. The three classifications 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 higher-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-1 employeeB. use the S-2 employeeC. use the S-3 employeeD. use either the S-1 or S-3 employee