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