Answer:
Discrimination is allowed in the case of not being able to drink because you are under age
Step-by-step explanation:
Discrimination is to treat someone with prejudice or unfairness due to a difference from the other people involved, in the cases A. B. and C we have examples of illegal discrimination that can not be allowed under any circumstances, on the other hand, case D is viable because through that "discrimination" you are in fact protecting the well being of an underage.