Option (B) is correct because the provided text states that the agreement of a trial balance 'is not an absolute proof of accuracy.' The context explains that there are specific errors that 'do not affect the equality of debits and credits,' such as debiting the correct amount in the wrong account or recording an equal debit and credit of an incorrect amount. These are examples of two-sided errors that keep the trial balance tallied. Conversely, if a one-sided error existed (which affects equality), the trial balance would not agree. Therefore, a tallied trial balance implies that while arithmetical accuracy exists, there may still be two-sided errors.