Answer:
C. Increase tariffs to protect domestic industries that will provide more jobs.
Step-by-step explanation:
Remember, the problem here according to the high natural rate of unemployment principle is the rate at which people lose their jobs. In other words, the problem not the lack of jobs, but the desired need to create job sustainability (protection).
Hence, the best plan that the candidate might present to lower the natural rate of unemployment is to Increase tariffs to protect domestic industries that will provide more jobs. By protecting these industries they can better sustain their workers thereby lowering the natural rate of unemployment.