How did some cities prevent the desegregation of public places? a. by closing public properties to everyone b. by filing lawsuits against the american gi forum c. by giving public land to private organizations d. by desegregating only one place at a time

I believe the answer is: C. by giving public land to private organizations 
To prevent desegregation, many cities decided to turn their publicly owned properties into privately owned.
Which means that governemnt have a new motive to prevent a certain member of minority groups to use a certain property, by saying that they have no control over how private sectors handle their own property.