Suppose that, in a multi-period inventory model, a (R,Q) replenishment policy is used. The probability that you have no inventory on-hand when your new shipment arrives equals
a) The in-stock probability
b) The critical ratio
c) Lost Sales
d) The gross margin
e) The ratio of inventory turns to days-of-supply
f) None of the above
it is equal to ________________ (fill in the blank)