The rate of a reaction is expressed as
\(+\frac{1}{2}\,\frac{d[C]}{dt}\,=-\frac{1}{3}\,\frac{d[D]}{dt}\) \(=+\frac{1}{4}\,\frac{d[A]}{dt}\,=-\frac{d[B]}{dt}\)
The reaction is
(a) 4A + B → 2C + 3D
(b) B + 3D → 4A + 2C
(c) A + B → C + D
(d) B + D → A + C