Farmers who sell their fruit and vegetables to consumers at roadside stands or farmer's markets use a consumer marketing channel.

Farmers who sell their fruits and vegetables directly to the consumers by placing stands on roadsides or through farmers' market use a Producer to Consumer marketing channel.

They are the producers of the products, and they are selling their products directly to the consumer of those goods. So they are basically engaging in the Producer to Consumer Channel of Marketing

i would say iii (3) because in order to compare a price you have to use as a reference other near stores because it's its

hope i explained myself