; (2) in subsection (d)(2), by striking or (o) each place it appears and inserting (o), or (w) ; and (3) by inserting at the end the following: (w) Clean octane standard (1) Aromatics (A) Annual average limitation Effective January 1, 2023, no refiner or importer shall sell motor vehicle gasoline that contains, on an average annual basis, an aromatic hydrocarbon content in excess of 17.5 percent. (B) Cap Effective January 1, 2023, no person shall sell motor vehicle gasoline that contains an aromatic hydrocarbon content in excess of 17.5 percent. (C) Regulations (i) Promulgation The Administrator of the Environmental Protection Agency shall promulgate regulations to implement this paragraph. Not later than January 1, 2023, the Administrator shall promulgate final regulations under the preceding sentence. (ii) Tradeable credits The regulations to implement this paragraph shall— (I) allow for the generation of tradeable credits to meet the requirement of subparagraph (A)