What should be used to make sure that an .mxd file can be opened in a previous version of ArcGIS?

What should be used to make sure that an .mxd file can be opened in a previous version of ArcGIS?
A . Save As command
B . Create Map Package
C . Export Map
D . Save a Copy command

Answer: A

Explanation:

Reference: http://webcache.googleusercontent.com/search?q=cache:Yjzi6cSqP8IJ:desktop.arcgis.com/en/arcmap/10.3/map/working-with-arcmap/saving-a-map.htm&client=opera&hl=en&gl=pk&strip=1&vwsrc=0