Answer:
A. incentives
Step-by-step explanation:
An incentive is a motivator to do something. Traditionally incentive is extrinsic, that is there is a reward given when an achievement is made. This is the rational for bonuses on the job. Where an employee is compensated for achieving a milestone at work.
Ultrinsic.com is using incentive of a cash reward for those that get As as a motivator for the students. Students pay an entry fee of $70 and if one student gets an A he will get the whole pool of funds. If more than one person gets an A they will share the money in the pool.
More students will be motivated to get As.