Q: 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: The Propulsion and Structural Test Facility is a facility of the George C. Marshall Space Flight Center in Huntsville Alabama. It was the site where the first single stage rockets with multiple engines were tested.This site was built in 1957 by the Army Ballistic Missile Agency and was the primary center responsible for the development of large vehicles and rocket propulsion systems. The Saturn Family of launch vehicles was developed here under the direction of Wernher von Braun.
Question: The document can be classified to which topic?
Options: 1)Company, 2)Artist, 3)Animal, 4)Building
A:
4