Q.Errors not affecting the agreement of trial balance are :

Errors of principle do not affect the agreement of the trial balance, so the answer is (b).

Some errors leave the trial balance in agreement because the debit and credit totals stay equal:

• Errors of principle — a transaction is recorded against accounting principles (e.g. purchase of an asset debited to an expense account), but an equal debit and credit are still posted, so the totals agree.
• Errors of complete omission and compensating errors also do not affect agreement. …