With the advancement of technology, scientists can determine the year the tree was cut by testing the wood. Therefore, the wood that survived in the ancient building can determine the year of construction of the ancient building. What assumptions is the above discussion based on? ['The wood in the ancient building was not left idle for a long time before use.', 'Ancient buildings used wood as a building material.', 'The construction of an ancient building usually uses only one kind of wood.', 'Well-preserved ancient buildings were built using the most durable wood.']