Starr, CPA, prepared and signed Cox's Year 1 federal income tax return. Cox informed Starr that Cox had paid doctors' bills of $20,000 although Cox actually had paid only $7,000 in doctors' bills during Year 1. Based on Cox's representations, Starr computed the medical expense deduction that resulted in an understatement of tax liability. Starr had no reason to doubt the accuracy of Cox's figures and Starr did not ask Cox to submit documentation of the expenses claimed. Cox orally assured Starr that sufficient evidence of the expenses existed. In connection with the preparation of Cox's Year 1 return, Starr is: