Which of the following is a radical equation?
A$x \sqrt{3}=13$
B$x+\sqrt{3}=13$
C$\sqrt{x}+3=13$
D$x+3=\sqrt{13}$
A$x \sqrt{3}=13$
B$x+\sqrt{3}=13$
C$\sqrt{x}+3=13$
D$x+3=\sqrt{13}$