Ext Audit

If an external auditor in the process of considering the company's financial statements came across an incident of fraud that took place in the year, he/she must a- qualify the accounts regardless of the size of the fraud b- report to the shareholders by the way of a note to the accounts, regardless of the size of the fraud c- qualify the accounts only if the fraud is material and not properly recorded in the accounts d- report to the shareholders by a note to accounts, but only if fraud is material why is the correct ans C? why would the auditor qualify the accounts if there is a fraud?