The most difficult type of misstatement to detect fraud is based on __________.

The most difficult type of misstatement to detect fraud is based on omission of a sales transaction from being recorded. This type of fraud involves deliberately not recording a sales transaction, which can be challenging to detect because there may be no documentation or evidence of the unrecorded transaction in the company's financial records. It requires a more comprehensive and thorough examination of the company's internal controls and transaction records to uncover such omissions.