In the case of a petition under section
1154 of this title initially filed for an alien’s classification as a family-sponsored immigrant under section
1153
(a)(3) of this title, based on the alien’s being a married son or daughter of a citizen, if the petition is later converted, due to the legal termination of the alien’s marriage, to a petition to classify the alien as an immediate relative under subsection (b)(2)(A)(i) of this section or as an unmarried son or daughter of a citizen under section
1153
(a)(1) of this title, the determination described in paragraph (1) shall be made using the age of the alien on the date of the termination of the marriage.