1/ I believe the answer is: Securities
Securities would include all form of tradable assets which value could either goes up or down in the market. The uncertainty of this valuation provide opportunities for investors to speculate and obtain a profit based on their speculation.
2/ I believe the answer is: Medium of exchange
A medium exchange function refers to something that enable a certain object to be tradable with another object.
When you want to obtain milk before money exist, you would have to trade that milk with another object such as eggs or wool. After money is created, all objects could be exchanged with money rather than another object.
3/ I believe the answer is: Pension fund
When employees decided to create a pension fund, they would automatically entered an agreement to cut of some percentage of their earnings to be allocated to the pension fund. This allocated money cannot be obtained unless they enter retirement.
4/I believe the answer is: controlling the nation's paper currency
To be more precise, controlling the value of the currency. This is why during inflation, the feds would create several programs to reduce the amount of paper money that circulated in the market. This would make the currency become 'rarer' and increase its value overtime.
5/ I believe the answer is: Monetary
Monetary policy is the type of regulations that initiated by the central government in order to control the money supply.
This could be done by policies such as increasing interest for saving or creating government owned bond
