Rose and McMullin, a regional public accounting firm, has recently accepted a contract to audit On-the-Spot. Inc, a mobile vending senice that provides vending machines for targe events. On-the-Spot uses a computerized accounting system, portions of which were developed Internally to integrate with a standard financial reporting system that was purchased from a consultant. What type of documentation will be most useful to Rose and McMullin in determining how the system as a whole is constructed? Systems documentation Program documentation Operator documentation User documentation