Concept: A good extension worker needs professional and personal qualities that help him or her serve farming communities effectively.
Explanation: The essential qualities include organisational ability, clear judgement, and initiative.
These skills enable the worker to plan activities, make sound decisions, and engage the target group properly.
Involvement in local politics is not a professional requirement and may reduce objectivity.
Therefore, it is not a quality of a good extension worker.
Answer: D. Involvement in local politics