Which One of the Following Is an Example of a Frictionally

Which one of the following is an example of a frictionally unemployed individual?

A) Martin, who lacks the skills necessary to be employed as a machinist.
B) Lee, who lost his job as an art director because of a recession.
C) Jan, who has a Ph.D.in economics, but is a bus driver.
D) Helena, who has just graduated from college and is searching for a job as an architect.