In this task, you are given a text which is the body of a document. You are given a question and options. Pick the correct number. Don't generate anything else apart from the numbers provided in options.

Context: Liouville is a small lunar impact crater that is located near the eastern limb of the Moon. It lies to the southeast of the larger crater Dubyago and was previously designated Dubyago S before being given a name by the IAU.The crater is circular and bowl-shaped with a small interior floor at the midpoint of the sloping interior walls. The western and northwestern rim is attached to a depression in the surface that has the appearance of a distorted crater formation.
Question: The document can be classified to which topic?
Options: 1)Album, 2)Artist, 3)Company, 4)NaturalPlace, 5)Athlete
4