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

The plateau period of a person in a job is when he rises to a certain point in his career, learned and grow in the position, and then level off for a while. If you reach this period it is best for you to be patient and learn all you can about the job. Thus, the answer is letter C. 

Provincial Government means, anything done before the commencement of the Constitution, the authority or person authorized at the relevant date or administer executive government in the Province in question.

Example:

Canada has 10 provinces, making it a provincial government form.