In the following java statement the sqrt$()$ method from the Math class has been used to find the square$-$root value of $5\mathrm{.}6.$ Which of the following modifiers has been used in declaring the sqrt$()$ method so that it can be called without creating any reference$-$variable of Math class?

System.out.println$($Math$.$sqrt$(5\mathrm{.}6))$;

A$.$ final

B$.$ protected

C$.$ private

D$.$ static