Suppose you had invested in 500 units of a U.S. stock market index at the end of February 2009 at a price of $350.With the index at $453 at the end of July 2009, which of these investments on that date ensures a minimum portfolio return of 25%for the 6 months starting the end of February 2009 and ending the end of August 2009?

• A.Buy 1-month calls on 500 units of the U.S. stock market index with a strike price of $437.50 per unit and a premium of $24 per unit.
• B.Buy 1-month puts on 500 units of the U.S. stock market index index with a strike price of $455 per unit and a premium of $17 per unit.
• C.Buy 1-month calls on 500 units of theU.S. stock market index with a strike price of $455 per unit and a premium of $13 per unit.
• D.Buy 1-month puts on 500 units of theU.S. stock market index with a strike price of $437.50per unit and a premium of $10 per unit.
• E.None of them.