When I was in school, every child who purchased a school lunch from the cafeteria was legally required to be given the choice of milk, chocolate milk, or soy milk.
We even had a “local” farm who had a contract with the school district to have milk vending machines that sold 20 ounce bottles of strawberry, mocha, etc milks. That lasted until the district signed a contract with Pepsi, who was then granted the right to have their beverages be the only drinks to be sold in vending machines.