(A) $[B]_\text{max}=[A_o]\big(\frac{k_1}{k_2-k_1}\big)^{\large{k_2/k_2+k_1}}$ <\p>
(B) $[B] = \large\frac{k_2[A_o]}{k_2-k_1}$$\big(e^{-k_2t}-e^{-k_1t})$ <\p>
(C) $[C] = [A]_0$$ \big ( 1 - \large\frac{k_1 e^{-k_2t} - k_2e^{k_1t}}{k_2+k_1}$$\big)$ <\p> (D) $t_\text{max} = \large\frac{1}{k_2-k_1}$$\ln \large\frac{k_1}{k_2}$, the time at which concentration of $[B]$ is maximum