Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Most derivatives are priced by:
Option A:assuming that the market offers arbitrage opportunities.
Option B:discounting the expected payoff of the derivative at the risk-free rate.
Option C:applying a risk premium to the expected payoff of the derivative and its risk.

Answer: B