surviving divorced father
(6) The term “surviving divorced father” means a man divorced from an individual who has died, but only if (A) he is the father of her son or daughter, (B) he legally adopted her son or daughter while he was married to her and while such son or daughter was under the age of 18, (C) she legally adopted his son or daughter while he was married to her and while such son or daughter was under the age of 18, or (D) he was married to her at the time both of them legally adopted a child under the age of 18.