Flipping Burgers at the Local Drive-Thru Is Marla's First Job

Flipping burgers at the local drive-thru is Marla's first job. She has no work experience, no marketable skills. Which one of the following would you suggest her manager do to keep Marla motivated to perform at her highest level?

A) Pay her more than minimum wage.
B) Pair her with a long-term employee to train her in her job tasks.
C) Offer her a promotion if she meets specific goals.
D) Recognize her best performance with public praise.