Since John is the supervisor at a local factory who receives requests from the workers to teach them to fix the machine they use.
Explanation:
This means that he is superior among them. So, he should teach them how to fix the machine because he is an important and senior person of the firm under whom the workers are employed. Therefore, he should train them in order to avoid any difficulties in future and also, the workers can work by themselves without asking him to fix the issues all the time.
