A company purchases one of its raw materials from a particular supplier whose delivery times can vary. Details of lead times and production are as follows

$\backslash$table$[[$Maximum lead time,$12$ days$],[$Average lead time,$8$ days$],[$Minimum lead time,$4$ days$],[$Maximum usage,$600kg$ per day$],[$Average usage,$450kg$ per day$],[$Minimum usage,$300kg$ per day$]]$

What should be the reorder level for this raw material?

$\backslash$table$[[$A$,$I,$],],[B,1,,],[$C$,,,],[$D$,$I