Questions 9~11 refer to the following information. The daily changes of the market can lead investors astray. The ups and downs make the tendency to look at the portfolio’s performance frequently too tempting. This means investors are likely to perceive more risk, forgetting about their long term goals. When investors log into their trading accounts they can see the potential gain or loss of all of their assets. They can also see the day change on assets which are coded gain and loss. However, it's believed that those who look less get more. For instance, if you look at FTSE index from today to tomorrow there is a roughly 50% chance that it has gone up or down. If you look at it over a year you may find that 60%-65% of the time it is going up. And if you look over a five-year period you will find that 90% of the time it goes up. What’s the author’s suggestion to investors?
A. Keep themselves from checking their trading accounts. B. Pay attention to long-term interests rather than short-term ones. C. Avoid risks in terms of their investment plans. D. Stick to one portfolio for at least five years.