Accounting · Trial Balance and Errors

Consider the following errors made by a bookkeeper: 1. A purchase invoice for $800 was correctly recorded in the Purchases account but entirely omitted from the Payables account. 2. A cash receipt of $1,500 from a customer was correctly debited to the Bank account but mistakenly debited to the Sales Revenue account instead of credited to Receivables. 3. The acquisition of new machinery for $5,000 was correctly recorded as a debit to the Machinery account but credited to the Bank account as $500. 4. A cash sale of $300 was completely omitted from the accounting records. Which of these errors, if occurring individually, would prevent the trial balance from balancing?