According to U.S. GAAP, which of the following provides the most reliable measure for fair value measurement? a. Unobservable inputs used by the reporting entity when modeling how the market would determine the fair value of the asset or liability in question b. Observable market data serving as inputs into estimates into present value-based measurements such as foreign exchange rates. c. Observable quoted market prices in active markets for identical assets or liabilities d. Quoted market prices of identical assets or liabilities in inactive markets