What items should be calculated when analyzing the accounts receivable and allowance for doubtful accounts?
(a) The growth rates of sales and inventories.
(b) The growth rates of sales, accounts receivable, and the allowance for ­doubtful accounts, as well as the percentage of the allowance account ­relative to the total or gross accounts receivable.
(c) The common-size balance sheet.
(d) The growth rates of all assets and liabilities.