The correct answer is: A. Ensure there are no ghost workers.
A surprise check on the pay day is a common audit procedure to ensure that there are no ghost workers. Ghost workers are employees who are not actually working for the company but are still being paid. This can be a major problem, as it can lead to significant financial losses. By conducting a surprise check, the auditor can verify that all employees who are being paid are actually working for the company.
The other options are also important audit procedures, but they are not the primary purpose of a surprise check on the pay day. Option B, ensuring that the casual workers employed are authorized by the supervisor, is important to ensure that only authorized employees are being paid. Option C, testing procedures for distributing paycheques, is important to ensure that paycheques are being distributed correctly. Option D, obtaining an understanding of the internal control system, is important to understand how the company’s payroll system works. However, the primary purpose of a surprise check on the pay day is to ensure that there are no ghost workers.