Which of the following correctly references the macro named Printdsn as shown here:
%macro printdsn(dsn,vars); %if &vars= %then%do; proc print data=&dsn; title "Full Listing of %upcase(&dsn) data set"; run; %end; %else%do; proc print data=&dsn; var &vars; title "Listing of %upcase(&dsn) data set"; run; %end; %mend;