In January there was a large drop in the number of new houses sold, because interest rates for mortgages were falling and many consumers were waiting to see how low the rates would go. This large sales drop was accompanied by a sharp rise in the average price of new houses sold.
Which of the following, if true, best explains the sharp rise in the average price of new houses ？（）

A．Sales of higher-priced houses were unaffected by the sales drop because their purchasers have fewer constraints limiting the total amount they pay.

B．Labor agreements of builders with construction unions are not due to expire until the next January.

C．The prices of new houses have been rising slowly over the past three years because there is an increasing shortage of housing.

D．There was a greater amount of moderate-priced housing available for resale by owners during January than in the preceding three months.

E．Interest rates for home mortgages are expected to rise sharply later in the year if predictions of increased business activity in general prove to be accurate.

《韩非子•五蠹》中记载“上古之世，人民少而禽兽众，人民不胜禽兽虫蛇，有圣人作，构木为巢，以避群害，而民悦之，使王天下”，请问这句话说的是传说中的什么人？