The correct answer is D. sideward delegation.
Delegation is the process of assigning tasks and responsibilities to others. It can be done in a number of ways, including oral delegation, written delegation, downward delegation, and sideward delegation.
Oral delegation is the most common form of delegation. It involves simply telling someone what you want them to do. This can be effective in some cases, but it can also lead to misunderstandings and confusion.
Written delegation is more formal than oral delegation. It involves creating a document that outlines the tasks and responsibilities that are being delegated. This can help to avoid misunderstandings and ensure that everyone is on the same page.
Downward delegation is when a manager delegates tasks to their subordinates. This is the most common type of delegation.
Sideward delegation is when a subordinate delegates tasks to another subordinate of the same rank. This is less common than downward delegation, but it can be effective in some cases.
In the case of the question, the delegation of some of his duties by a subordinate to another subordinate of the same rank is called sideward delegation. This is because the subordinate is delegating tasks to another subordinate of the same rank, rather than to their manager or to a subordinate of a lower rank.