Plaintiff Plains Bank extended a line of credit to Defendant Doris. The repayment of

expenses incurred have been due for several months, and Plains Bank filed suit to recover the

full amount due on the credit account. Plains Bank attached to its petition a sworn accounting

of all expenses incurred on Doris' credit account. Doris' answer is due this week, and she

wishes to challenge the accuracy of the accounting of expenses on her account, as attached

by Plains Bank to its petition.

What must Doris include in her answer in order to be able to challenge the accuracy of the

sworn accounting attached to Plains Bank's petition at trial?