Answer:
b. Rotate service people in different tasks.
Step-by-step explanation:
Service time variability is the level of inconsistency in service delivery to customers that are waiting to be attended to.
When there is rotation of service people in different tasks, it results in greater service time variability. This is because the time it will take to rotate staff reduces time focused on attending to customers.
Also when a new staff comes to a work station there is a time he will spend becoming familiar with the new role. This learning period also causes delays to the customer.