If you reach a "plateau period" in your job,

Abe patient and learn all you can about the job.
Bcomplain to your supervisor.
Csomething serious has gone wrong.
Dimmediately begin to look for another job.

Verified Answer :

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.