in which of the following situations would the standard mileage rate be allowed?

a. Addie, a rural mail carrier, reciev3d qualified reimbursement.
b. Oliver used the actual expense method when his vehicle was placed in service two years ago.
c. Isaac has five cars used at the same time (a fleet of vehicles) in his buisness.
d. Blanche uses her vehicle 80% for buisness and maintains a mileage log with all required information