; and (2) to identify the parameters and processes considered under subsection (b) that— (A) are the most important, in that they have the most impact on the magnitude or uncertainty of the applicable simulated metrics; and (B) can be further characterized or optimized to improve the modeling and determination of the optimal resource portfolio for the applicable power grid region or service area. (d) Existing approaches; State requirements (1) In general The reliability standards approved under subsection (a)— (A) shall take into consideration, and shall allow for the continued use of, any probabilistic modeling in use by an electric utility, a Regional Transmission Organization, or an Independent System Operator as of the date of enactment of this Act; and (B) shall not preempt, or exempt any electric utility, Regional Transmission Organization, or Independent System Operator from compliance with, any probabilistic modeling requirement under State law. (2) Requirements To the maximum extent practicable, the reliability standards approved under subsection (a) shall allow for compliance with those reliability standards to be achieved— (A) in a manner consistent with— (i) the probabilistic modeling described in subparagraph (A) of paragraph (1); and (ii) any requirements described in subparagraph (B) of that paragraph; and (B) by demonstrating— (i) the use of probabilistic modeling in accordance with subparagraph (A) or (B) of that paragraph; and (ii) that the probabilistic modeling adequately reflects, or has been modified or used in a manner to adequately reflect, the requirements described in subsections (b) and (c).