Final answer:
The best method of achieving internal control over advanced IT systems is through controls written into the computer system, as they provide comprehensive, real-time protection and error prevention.
Step-by-step explanation:
The best method of achieving internal control over advanced IT systems is through the use of controls written into the computer system. These are often referred to as application controls or system controls and can include things like user authentication, access controls, input controls, processing controls, and backup and recovery procedures. Such controls are integral to safeguarding assets, maintaining data integrity, and ensuring the operational effectiveness of the system.
Options like batch controls, equipment controls, and documentation controls also play important roles in internal control, but they are not as comprehensive or integrated as controls written into the computer system itself. Batch controls are useful for ensuring data integrity during processing of large volumes of transactions, equipment controls help protect physical assets, and documentation controls ensure proper record-keeping. However, they do not provide the same level of real-time, automated protection and error prevention as controls embedded in the system.