In the context of fixed$-$quantity systems, $\_\_\_\_\_$ is defined as the on$-$hand quantity $($OH$)$ plus any orders placed but which have not arrived minus any backorders $($BO$).$

Question $3$ options:

a$)$

inventory position

b$)$

the reorder point

c$)$

a stock$-$keeping unit

d$)$

work$-$in$-$process inventory