Here's a problem to solve: At which type of margin does mountain building produce mountains composed entirely of preexisting crust material?

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

- A: divergent boundary between two oceanic plates
 
- B: divergent boundary between an oceanic plate and a continental plate
 
- C: convergent boundary between an oceanic plate and a continental plate
 
- D: convergent boundary between two continental plates
 