(A) [B]max=[Ao](k1k2−k1)k2/k2+k1 <\p> (B) [B]=k2[Ao]k2−k1(e−k2t−e−k1t) <\p> (C) [C]=[A]0(1−k1e−k2t−k2ek1tk2+k1) <\p> (D) tmax=1k2−k1lnk1k2, the time at which concentration of [B] is maximum