Answer:
Job enrichment.
Explanation:
The work design technique that Mary is implementing in her store is the job enrichment which is a technique that provides greater autonomy to the organization's employees, that is, employees have the possibility to participate in the decision-making process, greater control and greater flexibility to organize your work.
This technique has the main advantage of increasing the motivation of employees, who feel more valued by the organization, more confident in carrying out their function and more capable of innovating and developing their skills and competences.