Please give a brief reasoning

Multiple-choice answers. 2. Which of the following is true about storage costs for commodities in futures and forward markets? (a) Storage costs must be accounted for only if the investor actually accepts physical delivery (b) Storage costs must be accounted for even if the contract is cash settled (c) Storage costs must be accounted for if the contract is physically settled, even if the investors reverse their positions before delivery (d) Storage costs must be accounted for only for futures markets, but not for forward markets