Use \programopt in one place.

Doc/ref/ref8.tex

@@ -34,7 +34,7 @@ in the namespace of \module{__main__}.
 \refbimodindex{__main__}
 
 Under {\UNIX}, a complete program can be passed to the interpreter in
-three forms: with the \program{-c} \var{string} command line option, as a
+three forms: with the \programopt{-c} \var{string} command line option, as a
 file passed as the first command line argument, or as standard input.
 If the file or standard input is a tty device, the interpreter enters
 interactive mode; otherwise, it executes the file as a complete