If In = ₀∫¹ dx/(1+x²)ⁿ; n∈N, then which of the following statements hold good?
a. 2nIₙ₊₁ = 2⁻ⁿ + (2n - 1)In
b. I₂ = π/8 + 1/4
c. I₂ = π/8 - 1/4
d. I₃ = π/16 - 5/48