Final answer:
Option C, switching from a 'house salad' to a salad bar with 40 items, is not an increase in service complexity.
Step-by-step explanation:
The answer to the question, “Which of the following is not an increase in service complexity?” is option C) A restaurant switches from “house salad” to a salad bar with 40 items. This is not an increase in service complexity because it is simply a change in the variety of items offered in the salad bar, rather than a change in the structure or operations of the restaurant. The other options involve adding new services or hiring additional staff, which would increase the complexity of the business.