Final answer:
When a manager uses positive or negative reinforcement, they aim to strengthen the behavior of task completion. Positive reinforcement adds something desirable, while negative reinforcement removes something undesirable to achieve this goal.
Step-by-step explanation:
If a manager uses positive reinforcement or negative reinforcement when an employee completes a task, the manager is trying to strengthen the behaviour of completing the task. This is because in operant conditioning, reinforcement, whether positive or negative, is aimed at increasing the likelihood of a behavior being repeated.
Positive reinforcement involves adding a desirable stimulus to increase a behavior. For example, praising an employee for good work or providing a bonus for achieving a target. Negative reinforcement involves removing an undesirable stimulus to increase a behavior. An example of this would be a manager stopping constant check-ins on an employee's progress once they have demonstrated they can complete tasks on time.
To summarize, the correct answer is: a. strengthen the behaviour of completing the task.