Answer: A) treating as crucial.
Step-by-step explanation:
When something is being prioritized out of others it means that it is being treated as if it is the most important thing out of all it's peers. This makes it a crucial measure.
In developing a system that would prioritize patient appointments with providers, the system is treating these appointments are crucial thereby ensuring that patients meet with their healthcare providers as soon as possible which would increase the chances of lives being saved.