Answer:
c. higher unemployment rate. If a larger portion of the adult population were teenagers , the natural rate of unemployment would be higher.
Explanation:
As provided teenagers have more frequent unemployment spells that means that the population of teenagers is usually unemployed, as they spend most of their time searching for the jobs rather than actually grabbing and working.
Whereas usually adults settle down and find a descent job, and work on such job. Accordingly they do not contribute much to unemployment.
Accordingly if more of the adults were of teenage then the rate of unemployment would drastically be high.