Marcus and Geoff decide to train together to participate in a triathlon. Geoff is doing it because he likes the challenge, but Marcus is only doing it because he wants to win the prize money. In terms of theory, Marcus is being motivated by a(n) drive.

Secondary drive

Explanation:

Drive refers to increased arousal and internal motivation to reach a particular goal.

Basically,there are two types of drive namely;

Primary drives: which  are directly related to survival and include the need for food, water, and oxygen.

Secondary drives: are those that are culturally determined or learned, such as the drive to obtain money, intimacy, or social approval.

Secondary drives are associated with primary drives because the satisfaction of secondary drives indirectly satisfies primary drives.

For example, Marcus wanting to participate in the triathlon because of the prize, if eventually he wins the prize(maybe money), it provides him with money that can be used to acquire food, shelter, and other basic needs, thereby indirectly satisfying these primary drives.