Which of these statements about the production order quantity model is false?

a. the production order quantity model is appropriate when the assumptions of the basic eoq model are met, except that receipt is noninstantaneous.
b. average inventory is more than one-half of the production order quantity.
c. because receipt is noninstantaneous, some units are used immediately and not stored in inventory.
d. all else equal, the smaller the ratio of demand rate to production rate, the smaller is the production order quantity.
e. none of these is false.