Answer: A. Jen is using money as a store of value.
Explanation:
A store of value regarding money simply means that money can be saved and then later exchanged in the future when it is needed without the value of the money deteriorating.
Medium of exchange is a function of money that is used when one makes purchases and makes payment. Deffered payment means that one can pay later when one does not have money to pay yet.
Therefore, the answer is A.