Answer:
The correct answer is option A) "John should make sure he trains the workers better, including how to fix the machine.
Explanation:
A supervisor´s task includes training people so that they can be more independant and effective at their jobs.
If john continues to fix machines instead of teaching them, he will not let them solve problems on their own.
If john tells them to figure it out by themselves, they run the risk of doing it wrong. Consequently, they can get hurt or break the machine.
And finally if John ignores the problem, it will not go away and worker will continue to ask him to fix the machine.