child
(2) “child” means an individual— (A) who— (i) is an offspring or adopted child of the participant, (ii) is a stepchild or recognized natural child of the participant and who received more than one-half support from the participant, or (iii) lived with the participant, for whom a petition of adoption was filed by the participant, and who is adopted by the surviving spouse of the participant after the death of the participant; (B) who is unmarried; and (C) who— (i) is under the age of 18 years, (ii) is a student under the age of 22 years (for purposes of this clause, an individual whose 22d birthday occurs before July 1 or after August 31 of the calendar year in which that birthday occurs, and while the individual is a student, is deemed to become 22 years of age on the first July 1 which occurs after that birthday), or (iii) is incapable of self-support because of a physical or mental disability which was incurred before the individual reached the age of 18 years;