Which of the following statements is true with regard to the reimbursement of employee business...

Which of the following statements is true with regard to the reimbursement of employee business expenses?

(a) Reimbursements of ordinary and necessary expenses may be subject to Federal income tax withholding.

(b) Excess reimbursements of ordinary and necessary expenses are never subject to withholding.

(c) Reimbursements received by an employee under a plan which contains a requirement to return excess amounts are automatically excluded from the definition of wages subject to withholding.

(d) Provided that reimbursements are received by an employee under a plan which requires the employee to substantiate the expenses to his employer, the amounts are automatically excluded from the definition of wages subject to withholding, without regard to whether the employee actually substantiates the expenditures.

(e) All statements are true.