Whether the court of appeals erroneously determined that the filed rate doctrine and the rule against retroactive ratemaking leave the Federal Energy Regulatory Commission no discretion to waive the operation of a filed market-based rate or retroactively to change or to adjust a market-based rate for good cause, such as the exigent circumstances caused by the 2014 Polar Vortex

QUESTION PRESENTED Whether the court of appeals erroneously determined that the filed rate doctrine and the rule against retroactive ratemaking leave the Federal Energy Regulatory Commission no discretion to waive the operation of a filed market-based rate or retroactively to change or to adjust a market-based rate for good cause, such as the exigent circumstances caused by the 2014 Polar Vortex. (i)