What is one way that futures differ from forward contracts?

	a.	Futures represent an obligation to buy or sell the underlying asset at a specified price, while forwards do not.
	b.	Futures are generally more customizable than forwards.
	c.	Futures are typically settled only at expiration, while forwards are settled daily through marking to market.
	d.	Futures are typically traded on exchanges, while forwards are usually traded over-the-counter.