Folk houses are closely related to the local natural environment. The following options reflect the architectural style of the folk houses in Southeast Asia: (a) cave b) igloo c) village d) highland.

The loess plateau has deep soil layers and strong uprightness. People dig holes to live in, which is warm in winter and cool in summer. The Inuit settlement is located in the cold zone, with cold climate, wide distribution of ice, easy access to materials and thick walls, which is conducive to maintaining indoor temperature, so an igloo was built to live in; In tropical desert areas, it is hot and dry all year round. In order to reduce heat transfer and sandstorm, more bunkers with small windows and ceilings were built. Southeast Asia is located in the tropical climate zone, which is hot and rainy. Living in an elevated house is conducive to ventilation and moisture prevention.

Therefore, choose: d.