Final answer:
Duplicate checking of calculations, preparing bank reconciliations, and monthly trial balances are examples of detective controls, which aim to identify and report errors after they have occurred.
Step-by-step explanation:
Duplicate checking of calculations and preparing bank reconciliations and monthly trial balances are examples of detective controls. Detective controls are designed to identify and report the occurrence of an error, omission, or other discrepancies in data or operations after they have occurred. The purpose of these controls is to discover and provide evidence of problems so that corrective action can be taken. Preventive controls, on the other hand, are designed to prevent errors or irregularities from occurring in the first place. Corrective controls are actions taken to fix problems that have been detected, and authorization controls regulate who has the permission to perform certain actions or access certain data. In conclusion, the type of control referred to in the student's question is detective control.