Among the following the A.P series is

Option(B): $5+9+13+\cdots$  is in A.P, $\therefore d=4$

Option(C): $\sqrt{7}+\sqrt{28}+\sqrt{63}+\cdots$  is in A.P, $\therefore d=\sqrt{7}$

Option(D): $\sqrt{2}+\sqrt{8}+\sqrt{18}+\cdots$  is in A.P, $\therefore d=\sqrt{2}$