I don't understand why B & C are not correct.

Problem 7-4 (Algo) Uncollectible accounts (LO7-5, 7-6] Raintree Cosmetic Company sells its products to customers on a credit basis. An adjusting entry for bad debt expense is recorded only at December 31, the company's fiscal year-end. The 2020 balance sheet disclosed the following: Current assets: Receivables, net of allowance for uncollectible accounts of $40,000 $ 482,000 During 2021, credit sales were $1,800,000, cash collections from customers $1,880,000, and $45,000 in accounts receivable were written off. In addition, $4,000 was collected from a customer whose account was written off in 2020. An aging of accounts receivable at December 31, 2021, reveals the following: Percent Uncollectible Age Group 0-60 days 61-90 days 91-120 days Over 120 days Percentage of Year-End Receivables in Group 60% 10 20 25 10 45 Required: 1. Prepare summary journal entries to account for the 2021 write-offs and the collection of the receivable previously written off. 2. Prepare the year-end adjusting entry for bad debts according to each of the following situations: Rad doht ovnence is actimated to ho 70of credit calec for the voar OU U-ou aays 61-90 days 91-120 days Over 120 days Required: 1. Prepare summary journal entries to account for the 2021 write-offs and the collection of the receivable previously written off. 2. Prepare the year-end adjusting entry for bad debts according to each of the following situations: a. Bad debt expense is estimated to be 2% of credit sales for the year. b. Bad debt expense is estimated by adjusting the allowance for uncollectible accounts to the balance that reduces the carrying value of accounts receivable to the amount of cash expected to be collected. The allowance for uncollectible accounts is estimated to be 10% of the year-end balance in accounts receivable. c. Bad debt expense is estimated by adjusting the allowance for uncollectible accounts to the balance that reduces the carrying value of accounts receivable to the amount of cash expected to be collected. The allowance for uncollectible accounts is determined by an aging of accounts receivable. 3. For situations (a)-(c) in requirement 2 above, what would be the net amount of accounts receivable reported in the 2021 balance sheet? Complete this question by entering your answers in the tabs below. Required 1 Required 2 Required 3 Prepare the year-end adjusting entry for bad debts. (If no entry is required for a transaction/event, select "No journal entry required" View transaction list View journal entry worksheet Credit No Transaction 1a. General Journal Bad debt expense Allowance for uncollectible accounts Debit 36,000 36,000 1. 2 . b. 39,700 Bad debt expense Allowance for uncollectible accounts 39,700 3 46,846 Bad debt expense Allowance for uncollectible accounts 46,846