Your friend, a coffee barista, joins a labor union that is organizing and campaigning for higher wages. She explains to you that while a higher hourly wage would be nice, what really motivates her to join is the strong sense of community she feels with her coworkers, many of whom are her age. Which type of incentive appears to be motivating your friend to participate in this interest group? Solidary incentive Material incentive Purposive incentive Tangible incentive