单项选择题

Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now listen to the passage. According to the professor, what characteristic of Earth’s moon should a theory of its origin be able to explain

A.The Moon has no water.
B.The Moon contains almost no iron.
C.Thy Moon is the largest moon in the solar system.
D.Tile Moon does not have a moten core.