Accounting for materials-maximum level

data relating to one particular stores item are as follows: average daily issue 70 units maximum daily issues 90 units minimum daily issues 50 units lead time for the replenishment of stock 11 to 17 days reorder quantity 2000 units reorder level 1800 units what is the maximum stock level (in units) for this stores item? A.2950 B.3100 C.3250 D.3800 my working: reorder level : 90 x 17 = 1530 units maximum level : 1530+2000-(11x50) = 2980 units please help why not get the correct answer is C.3250 ? thank you