An annuity payable to a child under subsection (d) of this section, or under section
2052
(c) of this title, shall begin on the day after the date on which the participant or retired participant dies or, in the case of an individual over the age of 18 who is not a child within the meaning of section
2002
(b) of this title, shall begin or resume on the first day of the month in which the individual later becomes or again becomes a student as described in section
2002
(b) of this title. Such annuity may not commence until any lump-sum that has been paid is returned to the fund.