Which of the following would NOT be an acceptable method to account for bad debts if accounts receivable is a material aspect of a companys operations?

		wait until the account becomes uncollectible, and then recognize bad debt expense
		estimate a percent of future uncollectible accounts at the time of each credit sale, and assign this amount to an allowance for uncollectible accounts
		periodically conduct an aging of accounts receivable to determine the size of the allowance for uncollectible accounts.