Final answer:
The activity related to payroll that is not an effective control plan is delivering paychecks to supervisors for distribution.
Step-by-step explanation:
The activity related to payroll that is not an effective control plan is (A) After their preparation, paychecks should be delivered directly to the employees' supervisors for distribution to the employees. This control plan is not effective because it creates an opportunity for the supervisors to manipulate or mishandle the paychecks, leading to potential fraud or errors in distribution. Instead, it is recommended to deliver paychecks directly to the employees themselves, or to use secure and traceable methods of distribution.