How Can a Decrease in the Unemployment Rate from 21

How can a decrease in the unemployment rate from 21 percent to 17 percent be illustrated?

A) as an inward shift of the production possibilities curve
B) as a movement from a point outside the production possibilities curve to a point farther from the production possibilities curve
C) as an outward shift of the production possibilities curve
D) as a movement from a point inside the production possibilities curve to a point closer to the production possibilities curve