An accrual basis taxpayer may deduct an expense if economic performance has occurred and:

a. the all events test has been met and the amount of the obligation can be determined with reasonable accuracy.

b. the all events test has not been met, but the amount of the payment can be fixed with reasonable accuracy.

c. the all events test has been met, but the amount of the payment cannot be fixed with reasonable accuracy.

e. None of the above.