Whose Social Security benefit is included in the calculation of the maximum family benefit for those eligible for benefits based on a retired worker's fully insured status? I. The retired worker's benefit. II. A caregiver spouse's benefit for caring for a qualified disabled child. III. A dependent child's benefit. IV. The retired worker's former spouse. a. III and IV. b. I, III, and IV. c. I, II, and III. d. I and