Answer: The correct answer is choice a.
Explanation: The continuous review model works under the assumption that there is a constant demand for a product, regardless of other factors. There is a preset level of inventory, and when it gets to that level the product is automatically ordered and additional items are brought back into inventory. This makes choice a the one that is NOT an assumption - the order quantity is not constant regardless of demand. The item is not ordered until a preset order point is reached.