Final answer:
The IRS standard business mileage rate for 2018 is c) 54.5 cents per mile, which is used for calculating deductions for business vehicle use.
Step-by-step explanation:
The IRS standard business mileage rate for 2018 is C. 54.5 cents per mile. This rate is used by businesses and individuals to calculate deductions for the business use of a car, van, pickup, or panel truck.
The IRS adjusts this rate annually based on a study of the fixed and variable costs of operating a vehicle, including depreciation, insurance, repairs, tires, maintenance, gas, and oil.