For the reaction, $A+3B\to 2C+D$ which one of the following is not correct?

For the given reaction,

$\mathrm{A}+3\mathrm{B}\to 2\mathrm{C}+\mathrm{D}$

Rate expression;

$-\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}=-\frac{1}{3}\frac{\mathrm{d}\left[\mathrm{B}\right]}{\mathrm{dt}}=\frac{1}{2}\frac{\mathrm{d}\left[\mathrm{C}\right]}{\mathrm{dt}}=\frac{\mathrm{d}\left[\mathrm{D}\right]}{\mathrm{dt}}$

Option (A) is correct.

Rate of disappearance of A = Rate of formation of D

$-\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}=\frac{\mathrm{d}\left[\mathrm{D}\right]}{\mathrm{dt}}$

Option (B) is correct

Rate of formation of C = $\frac{2}{3}\times$  Rate of disappearance of B

$-\frac{1}{2}\frac{\mathrm{d}\left[\mathrm{C}\right]}{\mathrm{dt}}=-\frac{1}{3}\frac{\mathrm{d}\left[\mathrm{B}\right]}{\mathrm{dt}}$

$\therefore \frac{\mathrm{d}\left[\mathrm{C}\right]}{\mathrm{dt}}=\frac{2}{3}\frac{\mathrm{d}\left[\mathrm{B}\right]}{\mathrm{dt}}$

Option (C) is also correct

Rate of formation of  D =$\frac{1}{3}\times$ Rate of disappearance of B

$\therefore \frac{\mathrm{d}\left[\mathrm{D}\right]}{\mathrm{dt}}-\frac{1}{3}\frac{\mathrm{d}\left[\mathrm{B}\right]}{\mathrm{dt}}$

Option (D) is incorrect because the rate of disappearance of A is $\left(\frac{1}{2}\right)$ times to that of rate of formation of C.

$-\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}=\frac{1}{2}\frac{\mathrm{d}\left[\mathrm{C}\right]}{\mathrm{dt}}$