Listed below are costs of providing an airline service. Classify each cost as (a) either variable or fixed, and (b) either direct or indirect by selecting the appropriate dropdowns. Consider the cost object to be a flight. Flight attendants and pilots are paid based on hours of flight time. Cost Variable or Fixed Direct or Indirect 1 . Fuel used in planes 2. Depreciation (straight-line) on ground equipment 3 Flight attendant wages 4 Aircraft maintenance manager salary 5 Pilot wages 6. Customer service salaries 7. Snacks served on airplanes B. Depreciation on office equipment