Here's a problem to solve: The day before the class is going to do a lab experiment, their teacher reminds them not to wear open shoes to school the next day. Which rationale best explains their teacher's request?

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

- A: to prevent spills of chemicals
 
- B: to prevent injury to toes or feet
 
- C: to keep them from getting tired feet
 
- D: to keep them grounded in case of shock
 