Which of the Following Errors Could Cause the Trial Balance

Which of the following errors could cause the trial balance totals to be unequal?

A) posting the debit portion of a journal entry incorrectly when the credit portion of the entry is correctly posted
B) failure to record a transaction or to post a transaction
C) recording the same transaction more than once
D) recording the same erroneous amount for both the debit and the credit parts of a transaction