[Solved] Which of the following is most clearly NOT an example of an incentive? A) social disapproval B) a pornographic movie C) a low blood glucose level D) the smell of rotten eggs Commercial Airline Travel: The aspect of aviation that involves operating aircraft for hire to transport passengers or cargo on scheduled or charter services. Electrical Service: Maintenance, repair, and installation services provided for electrical systems and components in buildings and infrastructure. Fixed Costs: Costs that do not vary with the level of production or sales, such as rent, salaries, and insurance premiums. Variable Cost: Expenses that change in proportion to the activity of a business, such as costs for raw materials that fluctuate with production volume.