Which of the following is an example of hedging?

	A.	Kodak uses silver to make film. They "lock in" the price of silver so that they know what their costs will be going forward.
	B.	Delta airlines biggest cost is jet fuel. They "lock in" the price of oil so that their fuels costs will not increase.
	C.	Marathon Oil does a great deal of business with Saudi Arabia. The U.S. dollar is worth 3.75 riyals (the currency in Saudi Arabia). If this rate fluctuates it can make a big difference to Marathon's profits. Marathon "locks in" this exchange rate.
	D.	All three of the above scenarios are examples of hedging.