With no explanation, chose the best option from "A", "B", "C" or "D". finally determined the Ramsey prices for each combination. While its description of this process is, charitably speaking, rather opaque, it appears that this involved finding the optimum total cost (including operating costs and incremental and fixed air traffic services costs) for each combination based on the demand elasticity and the difference between price and incremental cost. Subtracting out the operating costs yielded the “Ramsey price” for each category, including both incremental and fixed costs. Significantly, the study noted that “[t]he allocation of those common and fixed costs depends heavily on the overall flight cost. As the price of air traffic services becomes a smaller fraction of total costs, the optimization will assign a higher Ramsey price to higher cost flights (<HOLDING>).” GRA Study at 51. Finally, the Ramsey prices

A: holding that the petition must be signed by all defendants or the signer mustallege consent of all defendants
B: holding that all newly declared rules must be applied retroactively to all criminal eases pending on direct review
C: holding all else constant
D: holding the right of free speech is not absolute at all times and under all circumstances
C.