The OASDI program provides retirement benefits to covered employees and their dependents. Explain whether each of the following persons would be eligible for OASDI retirement benefits based on the retired worker's earnings record. Treat each situation separately.

a. A retired worker's unmarried son, age 25, who became totally disabled at age 15 because of an auto accident.

b. A spouse, age 63, of a retired worker who is no longer caring for an unmarried child under age 18.

c. A retired worker's spouse, age 45, who is caring for the 12-year-old daughter of the retired worker.

d. A divorced spouse, age 55, who was married to a retired worker for six years.