R, 1 byte:
T
T is an alias for the constant TRUE. So the output for the above is:
[1] TRUE
Since junk is allowed around the name, the “R” in there is the language name.
(As noted in a comment elsewhereAs noted in a comment elsewhere, pretty much any single letter and many glyphs will work equally well because they trigger the message “Error: …”, which contains “r”.)