For your first question, the option that is NOT a function of money is Currency exchange. While currency exchange is related to money, the primary functions of money are medium of exchange, store of value, and unit of account.
For the second question, the primary reason money is often preferred over bartering in transactions is It allows for the exchange of goods without needing a mutual desire. This means that with money, you do not need to find someone who has exactly what you want and who also wants what you have to offer.