Mention how a contact farmer can be considered as: 

A contact farmer is an individual selected within a farming community to act as a link between agricultural extension workers and other farmers. Key Points

• A contact farmer can be considered an opinion leader because they serve as a trusted source of information and influence within the farming community.
• They are chosen based on their experience, knowledge, and acceptance within the community.
• Opinion leaders in agriculture play a key role in adopting and spreading new techniques, encouraging fellow farmers to experiment with better farming methods.
• Their influence is based on practical expertise and credibility rather than formal authority, making them effective agents of change in rural areas. 

Hint

• A professional leader is someone with formal training and expertise, usually working in an official capacity, which does not align with the role of a contact farmer.
• An official leader holds a government or institutional position, while a contact farmer is an informal influencer.
• A lay leader refers to a non-expert guiding a group, but contact farmers are chosen for their specific agricultural knowledge and influence, making them more aligned with the role of an opinion leader.

Hence, the correct answer is opinion leader.