Which of the following best illustrates the application of due professional care during an audit...

The internal auditor began checking purchase requisitions for proper authorizations. He stopped when he discovered an instance of noncompliance. and he concluded the controls were ineffective.

The internal auditor discovered an instance where management did not follow the standard bidding processes. The auditor assessed the validity of management’sreasons for deviating from standard practice and the supporting documentation, and determined that the deviation was acceptable.

The internal auditor selected a sample of purchase orders with amounts greater than S5.000, the threshold at which the organization requires a bidding process. The auditor obtained documentation of the bidding process for each purchase order in the sample.

The internal auditor analyzed bidding documents provided by management. Management indicated that the documents were purchase orders issued to a sole-source vendor Based on the analysis and management's declaration, the internal auditor determined that the procurement process was effective.