A、CDs. B、Demand deposits. C、Fixed-term deposits. D、Building societies deposits. C根据对话可知，CDs比定期存款(fixed—term deposit)更加灵活，但利率较CDs

W: I know there are some elements which will affect the investors’ searches for the highest possible returns. What are they?
M: Risk aversion, lack of time, lack of skill, and other mortal conditions.
Q: Which of the following doesn’ t belong to the elements which will constrain the investors’ searches for the highest possible returns?

M: CDs can be traded in the money market at any time. They are more flexible than fixed-term deposits.
W: That’ s right. So banks usually offer slightly lower interest rates on them.
Q: Which of the following has a higher rate?