Here's a problem to solve: If two tectonic plates are each moving in opposite directions away from the mid-ocean ridge at a rate of 10 millimeters per year, how long will it take for the ridge to become 100 millimeters broader?

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

- A: 1 year
 
- B: 5 years
 
- C: 10 years
 
- D: 100 years
 