Answer:
E. The average time between two consecutive orders is 20 days.
Step-by-step explanation:
Vivian has sunglasses which costs it $20 each. The inventory holding needs to be for 5 days since the lead time is 5 days for each order. The holding cost for the inventory is $500 for the whole year. There will be 10 days in average when two orders are placed for the sunglasses.