Back in the dark ages when i was a student, we got no choices. there was one entree, the same two sides, a dessert, and plain milk. I do remember every monday was chili with cornbread, fridays were fish sticks with green beans and fries.
Fast forward to when my daughter was in school, at a very small country school and the students were given one entree, 2 or three sides, sometimes a dessert, plain milk, on fridays they got chocolate.
Today my nephews go to an extremely small rural school, (2 rooms). Parents take turns coming in and fixing lunches, or the kids take their own. Older kids travel to a high shool several miles away.
Here in the big city, there are two choices for entrees, 4 sides, you get two, a dessert, and several choices for drinks (juice, chocolate milk, plain milk, or water) Prices are around $3 for small kids, high schoolers pay $4. I beleive there are salad bars at most of the schools too.