Final answer:
When customers lose patience and walk away, Demand is effectively reduced, as there will be fewer customers waiting to be served and not all potential sales may be realized.
Step-by-step explanation:
When customers lose patience and walk away, what is effectively reduced is C. Demand. When demand is reduced, there are fewer customers waiting to be served, which could suggest that not all potential sales will be realized. This reduction in demand can also affect the store's perceived customer service levels, as it indicates that customers are unwilling to wait, possibly due to long waiting times or a lack of sufficient service capacity.
Capacity refers to the maximum number of customers that the service facility can handle at a given time, which is not directly affected by customers walking away. Instead, it is pre-determined by the facility's resources, such as the number of employees or available service stations. Service time is the amount of time it takes to serve a customer, and this is also not immediately impacted by customers leaving. Waiting time is the duration that customers spend in line before being served. While this might subsequently reduce as a result of fewer customers, it is not what is directly reduced when customers walk away dissatisfied.