; and (2) by adding at the end the following: (b) (1) (A) Subject to the conditions described in subsections (b) and (c) of section 304, discrimination (including exclusion from participation and denial of benefits) based on disparate impact is established under this title only if— (i) a person aggrieved by discrimination on the basis of age (referred to in this title as a person aggrieved ) demonstrates that an entity subject to this title (referred to in this title as a covered entity ) has a policy or practice that causes a disparate impact on the basis of age and the covered entity fails to demonstrate that the challenged policy or practice is related to and necessary to achieve the nondiscriminatory goals of the program or activity alleged to have been operated in a discriminatory manner