- The sun setting is a kind of event
- The sun rising is a kind of event
- The sun rising / setting occurs once per day
- Hence, the sun rising and setting is the event that occurs once per day

So, the sun rising and setting is the event that occurs once per day
Question: Which event occurs every day?
Context: - The sun setting is a kind of event 
- The sun rising is a kind of event 
- The sun rising / setting occurs once per day