Here's a problem to solve: A student determines the mass of a sample on a triple-beam balance. What should the student do before determining the mass of the next sample?

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

- A: adjust the height of the pan
 
- B: move all of the riders to zero
 
- C: move the beams rapidly up and down
 
- D: adjust the location of the mass markings
 