The correct answer is D. All of these.
Management by exception is a management technique by which management focuses on significant deviations from a plan. This means that management only takes action when there is a problem, such as when costs are too high or when sales are too low. This can help to save time and resources, as management does not need to constantly monitor every aspect of the business.
Costs are an important part of any business, and it is important to control costs in order to make a profit. Favourable items are items that are performing better than expected, and unfavourable items are items that are performing worse than expected. Management by exception can help to identify both favourable and unfavourable items, so that management can take action to improve performance.
Overall, management by exception is a useful tool for managers who want to focus on the most important aspects of their business. It can help to save time and resources, and it can help to improve performance.