A Trial Balance only verifies mathematical accuracy (i.e., total debits = total credits). If a transaction is posted to the wrong head of account but with equal debit and credit, or if a transaction is omitted entirely (both debit and credit omitted), or if a transaction is duplicated (both sides again equal), the Trial Balance remains balanced and detects none of these. Option D (an arithmetic error on one side) would cause an imbalance and would be detected.