Nami died five years ago. Tony, age 46, who is Nami's surviving spouse, has been raising their three children (Kerry, Mary, and Terry). Tony earns $21,000 a year. Nami was insured under Social Security when she died. Which of these relatives will not be eligible for a survivor benefit this year?

a. Kerry, who is age 15, qualifies for the child's monthly benefit.

b. Mary, who will be 19 next September, will continue to qualify until she graduates from high school this June.

c. As the surviving spouse, Tony qualifies for the fathers benefit while he is caring for a child under age 16.

d. Terry, age 20, qualifies for the monthly child benefit because he is a full-time college student.