Future contracts (BPP 273)

Hello Sir,
Could you please help me with this question? I chose answers 2 and 3, but the book says 2 and 4. Isn’t a futures contract less flexible compared to a forward contract?

In comparison to forward contracts, which TWO of the following are true in relation to futures contracts?

? They are more expensive
? They are only available in a small amount of currencies
? They are less flexible
? They may be an imprecise match for the underlying transaction