Let \(I_{n}=\int_{0}^{1} x^{n} \tan ^{-1} x d x\). If \(a_{n} I_{n+2}+b_{n} I_{n}=c_{n}\) for all \(n \geq 1\), then
(A) \(a_{1}, a_{2}, a_{3}\) are in G.P
(B) \(b_{1}, b_{2}, b_{3}\) are in A.P
(C) \(\mathrm{c}_{1}, \mathrm{c}_{2}, \mathrm{C}_{3}\) are in H.P
(D) \(a_{1}, a_{2}, a_{3}\) are in A.P Ans: (B,D)