An internal auditor wants to test the processing logic of a computer application during a...

Comprehensive and Detailed Explanation:

An Integrated Test Facility (ITF) creates fictitious test data within a live system without disrupting actual operations. This allows the auditor to test the processing logic of applications under real conditions, ensuring transactions are processed consistently and correctly.

Utility software (A) supports system operations but does not test logic.

Parallel simulation (C) reprocesses transactions in an auditor-controlled system, but this does not test logic in the live environment.

Generalized audit software (D) analyzes data but does not simulate processing logic.

Therefore, the most effective method to test application logic in real time is Integrated Test Facility (B), as it directly evaluates processing accuracy within the operational system.