Question

the most useful advantage of adding a vegetarian hot - food option to a school lunch menu is limiting the amount of food that is wasted by the school. presenting an additional choice for teachers and staff. providing an additional choice for students on restricted diets. reducing the cost of lunch options for students and teachers.

Explanation:

Vegetarian options are most beneficial for students with restricted diets like vegetarians. It directly caters to their dietary needs. While other options may have some merit, providing for restricted - diet students is the most useful advantage.

Answer:

providing an additional choice for students on restricted diets.