There are multiple ways to go about these prompts. My strategy was:
1. Look at the mission of the school. Most are generic, but some will have something unique, like providing primary care to the state's population in the case of a state school.
2. Figure out what underprivileged population the school serves, and if that population interests you, write about it.
3. Do some research and figure out if there is anything unique about the school. This is hard, but if you do it well, it can truly show them you are interested.
4. Last, you can focus on location, but if the program is in an in-demand area, this will be less effective.