Three inhabitants in a remote island are discussing their occupations, which are all different, in response to a visitor’s inquiry. As to their groups, little is known except that one of them is a Knight, who always speaks truthfully, another is a Liar, who always speak falsely, and the remaining one is a Knave, who make statements that are alternately truthful and false. It is also known that, each inhabitant holds precisely one occupation that is different from two of his companions.

Art
1. My job as the sunflower-seed extractor is the most favorable occupation.
2. Carl’s second statement is false.
3. Bill is not the shepherd.

Bill
1. Art is the olive processor.
2. I am not a knave.

Carl
1. Art and Bill are both shepherds.
2. I am the sunflower-seed extractor.

What group or groups are represented by the three speakers, and what are their occupations?