Which of the following situations would warrant the use of the standard mileage rate?

1. a taxpayer has five or more cars used at the same time (a fleet of vehicles) in his business.

2. a rural mail carrier's vehicle when the carrier received qualified reimbursement

3. a taxpayer has 80% business use of their vehicle and maintains a mileage log with all required information

4. a vehicle in subsequent years when standard mileage was not used the first year the vehicle was placed in service