The correct answer is: a) Wood and bamboo.
Traditional Sikkimese houses are often constructed using wood and bamboo. This is because wood and bamboo are abundant in Sikkim, and they are also strong and durable materials that can withstand the harsh weather conditions in the region. Wood and bamboo are also relatively easy to work with, which makes them a popular choice for construction.
Mud bricks, marble, and granite are also used in some traditional Sikkimese houses, but they are less common than wood and bamboo. Mud bricks are made from a mixture of mud, sand, and straw, and they are often used to construct the walls of traditional Sikkimese houses. Marble and granite are both types of stone, and they are sometimes used to construct the floors and roofs of traditional Sikkimese houses.
Wood and bamboo are the most common materials used in traditional Sikkimese houses because they are strong, durable, and easy to work with. Mud bricks, marble, and granite are also used in some traditional Sikkimese houses, but they are less common than wood and bamboo.