Which of the following would the BLS define as a discouraged worker?

Which of the following would the BLS define as a discouraged worker?

Select one:

a. Quinton, who has a doctorate in chemistry, but works full time as a taxi driver

b. Mary, who was laid off last year and who was looking for a full-time job until last month

c. Robert, a retired teacher, who works full time as a greeter at a discount store

d. Susan, who has been unemployed for the past three years and is looking for a part-time job