3. Material requirements planning (MRP) lot-sizing assumptions include which of the following?

I. All requirements for a given period are available at the beginning of that period II. Ordering decisions occur at regular time intervals III. Demand for future periods can be back ordered

a. I only

b. II only

c. I and II only

d. I and III only For questions 4–9 the following notation is used:

Cp = ordering cost

= average requirements CH = inventory carrying cost ($ per unit per week)