The traditional houses in this area are () A. caves B. bamboo buildings C. blockhouses D. tents.

A cave has the characteristics of warm winter and cool summer, which is suitable for the loess plateau area, and A does not meet the meaning of the question;

B Southeast Asia is mainly tropical, so residential buildings should pay attention to ventilation, heat dissipation and moisture prevention. Bamboo building has this feature, and B meets the meaning of the question;

C bunker is located in west Asia and other areas, which does not meet the meaning of the question;

D tent is easy to disassemble, suitable for nomadic people, and does not meet the meaning of the question.

Therefore, choose: B.