An entity's allowance for doubtful accounts has a balance of $74,500 cr. at January 1, 2021. The following transactions occurred during the year 2021: Accounts written off $66,000 Recoveries of previously written off accounts 8,400 Accounts receivable at December 31, 2021 - 0-30 days $1,150,000 30-59 days 465,000 60-89 days 125,000 Over 90 days 56,000 The entity's controller estimated that 1% of all accounts in the 0-30 day category will become uncollectible, 5% of accounts in the 30-59 day category, 25% of accounts in the 60-89 day category and 50% of accounts greater than 90 days. 21 20312 125,000 60-89 days Over 90 days 56,000 The entity's controller estimated that 1% of all accounts in the 0-30 day category will become uncollectible, 5% of accounts in the 30-59 day category, 25% of accounts in the 60-89 day category and 50% of accounts greater than 90 days. What is the bad debt expense for the year ended December 31, 2021? a) $19,500 b) $38,100 c) $57,600 d) $77,100