If Purchase Return and Sale Events Do Not Occur Every

Multiple Choice

If purchase return and sale events do not occur every day for each inventory item, then what function must be included in a set of queries intended to calculate quantity on hand of inventory? (Note: Since the question specifies "if purchase return and sale events do not occur every day" your answer choice should reflect something that could be omitted from the query set if those events do occur every day for each item) .

A) Parameters that allow users to specify the date constraints of interest
B) Inner join operations such that all sales and purchase returns are mapped directly to purchases
C) Date constraints applied only to the purchase date
D) Null to zero functions on the summed purchase return quantity and on the summed sale quantity fields in the final quantity on hand calculation
E) A beginning date constraint set to the date of the oldest purchase return or sale, whichever occurred most recently