Which statement is correct in C programming language?

printf$("$the value of $x$ is $\%$ f$",\%$ a$)$;

printf$("$the value of $x$ is $\%$ f$")$;

printf$("$the value of $x$ is $\%d,$ a$)$;

printf$("$the value of $x$ is $",$ a$)$: