If you reach a "plateau period" in your job,
a. be patient and learn all you can about the job.
b. complain to your supervisor.
c. something serious has gone wrong.
d. immediately begin to look for another job.

A "plateau period" is a perdiod which is stable, so there is not a big threat of loosing the job but also there isn't a good chance of promotion.

In any case you shouldn't despair and immediately look for a new job or complain! It's best to be patient and learn all you can- answer A.