Which of the following statements about on-the-job training is true?

Which of the following statements about on-the-job training is true?

A.It is appropriate as initial training for jobs that have no room for errors.

B.It requires that employees learn to perform more than one job.

C.On-the-job training is more complicated to set up than a simple apprenticeship program for individual tasks.

D.The results tell immediately whether the employee understands what the trainer is trying to teach.

what the answer?