Why do schools serve milk instead of water?

Explanation:

They serve milk because many children need the nutrition. It might seem antiquated, it began in the late 1900–1920's in public schools to provide food for impoverished kids. Some high schools offer a variety of drinks including water, but by that age kids should know better about what to consume.

i don't know I think it's because they have water fountain and they are probably just lazy to get water or can't afford it

the correct option is c