Final answer:
Feedback is actually essential to MBO and is not something that detracts from its effectiveness. Elements such as setting realistic goals, specific goals, and individual planning and control all contribute positively to MBO.
Step-by-step explanation:
The question concerns Management by Objectives (MBO), which is believed to be effective due to various factors except one. The correct option that does not contribute to the effectiveness of MBO is d. feedback. Feedback is actually integral to MBO as it aids in monitoring and evaluating the progress towards goals. On the contrary, a) setting realistic and acceptable goals, b) setting specific goals, and c) individual goal setting, planning, and control all contribute significantly to the effectiveness of MBO. These aspects align with the core principles of MBO, which include setting achievable and appropriate goals that are both measurable and motivational, ensuring that the goals are relevant and time-bound to encourage individual commitment and drive.