Which of the following employees exhibits organizational citizenship behavion?

Kelly: A hardworking employee who is willing to work overtime for her company if a project necessitates it

Sam: An astute employee who is always on the lookout for better jobs

Morgan: An efficient manager who, as a matter of principle, never consents to work on weekends

Vivian: An agreeable manager with a high need for affiliation and a low need for achievement

Gary: An efficient manager who doesn't work beyond the minimum hours stipulated by his company