8. Refers to both physical and mental efforts like the works of farmers, fishermen, workers, lawyers, doctors, etc. a. Capital b. Labor C. Land d. Entrepreneurial activity 9. Which of the following is not a part of the operation system? a. Input b. Processor C. Output d. Fixed capital D 10. The following are examples of indirect costs except; a. Office costs b. Selling costs c. Electricity and water bills d. Health insurance​