Under the perpetual inventory system, what is the difference between a sales return and a sales allowance?

Under the perpetual inventory system, what is the difference between a sales return and a sales allowance?

A sales return requires a debit to Sales Returns and Allowances, but a sales allowance does not.

A sales return reduces the amount receivable from the customer, but an allowance does not.

A sales allowance is deducted from Sales revenue to calculate net sales, but a sales return is not.

A sales return involves an adjustment to Merchandise inventory, but a sales allowance does not.