If the premiums of call options for a fixed expiration time increase with strike price, then you can extract arbitrage with a [ Select the correct answer to fill in the sentence from: "strangle", "ratio", "bull", "bear", "None of the other responses.", "butterfly", "straddle", "box"] spread constructed from [ Select the correct answer to fill in the sentence from: "calls", "puts", "forwards", "None of the other responses.", "multiple types of securities listed here", "stock"] .

True or False: The risk-free rate for a foreign currency can be treated like a dividend rate, with the currency being treated as a stock in the domestic security valued according to its exchange rate.