A firm which plans to buy oil might anticipate a period of market volatility and wish to protect its expense against price fluctuations. The firm should:

A. enters a long position in oil futures or purchase a call option on oil.

B. enters a long position in oil futures or purchases a put option on oil.

C. enters a short position in oil futures or purchase a call option on oil.

D. enters a short position in oil futures or purchases a put option on oil.