; (2) examine the current understanding of background sources of ozone and the contribution of such sources to ground-level ozone in the United States to identify gaps in knowledge that need to be addressed with additional research; (3) examine challenges in quantifying the sources of background ozone and the contributions of each such source to ground-level ozone on a regional scale in the United States and identifies specific research needs to address these challenges; (4) include an outline of a plan for a research and development program, including specifications for costs, timeframes, and responsible agencies, to support analysis and demonstration of background ozone trends, including by— (A) improving collection and observational infrastructure; (B) improving confidence in model outputs; (C) reducing uncertainties in estimates of background ozone; and (D) making background ozone research outputs more useful and accessible to decision-makers; and (5) identify opportunities for international engagement that may facilitate increased research collaborations that improve understanding of ozone trends. (b) Report As a condition of any agreement under subsection (a), the Administrator shall require that the National Academies transmit to Congress a report on the results of the study under subsection (a) not later than 24 months after the date of enactment of this Act.