Suppose the daily demand of a project follows a normal distribution with the mean of 30 units and the standard deviation of 5 units. Lead time is 4 days. The ordering cost is $400 per order, and the inventory holding cost is $20 per unit per year. A cycle service level (probability of no stockout) of 95% is required. Using the fixed order quantity model, what is the safety stock required?a. 0b. 13c. 17d. 20e. 25