In $\Delta ABC,$ with usual notation. Observe the two statements given below:(I) $rr_1r_2r_3=\Delta ^2$ (II) $r_1r_2+r_2r_3+r_3r_1=s^2$ Which of the following is correct ?

(a) Both I and II are true

(b) I is true, It is false

(c) I is false, II is true

(d) Both I and II are false

(a) Both I and II are true