Here's a problem to solve: On December 12th a snowstorm in a city produced 20 centimeters of snowfall. When can this event be used to describe the climate of the region?

Among the 4 following options, which is the correct answer?

- A: if the snowfall set a record
 
- B: if the snowfall was unusual for the area
 
- C: if the snowfall was consistent with weather in December over time
 
- D: if the snowfall remained on the ground for longer than one month
 