I'm pretty new to using GIS. I'm building a map on top of the imagery basemap provided with ArcMap. When I went to add my first layers, a warning popped up with the titles "Geographic Systems Warning." It says "The following data sources use a geographic coordinate system that is different from the one used by the data frame you are adding into." My layer is in GCS_North_American_1983. I understand that I need to transform the data. When I click the transformations tab, it seems like my option is to transfrom from GCS_North_American_1983 to GCS_WGS_1984.
My question is: there is a drop down box that says "Using." It seems to give options of ways to transform the data. The defualt option is "none." Is it best for me to choose one of these options or for me to choose none?