which of the following statements is true? 

(i) If two products have the same coefficient of variation, they must hold the same number of days of safety inventory (irrespective of standard deviation), if they want the same cycle service level (CSL). 

(ii) If two products have the same coefficient of variation, the product with the higher standard deviation must hold more days of safety inventory, if they want the same CSL. 

(iii) If two products have the same standard deviation, they must hold the same number of days of safety inventory, if they want the same CSL. Explain why?