Question

Can anyone help me with a couple of these questions Please will give medals
1. To trade stocks in a stock market is called all of these except _____
A. exchange
B. buy/sell
C. open market * (my answer )
2. closing costs are calculated based on ____
A. down payments
B., selling price of the house
C. loan amount minus down payment
D. selling price of the house minus down payment * (my answer)

3. which savings instrument is considered the riskiest
A. stock
B. CD
C. treasury bond (my answer)
D. savings account