Nomenclature is governed by certain universal rules. Which one of the following is contrary to the rules of nomenclature?

The ratio of the speed of the electrons in the ground state of hydrogen to the speed of light in vacuum is

If $u=\sin ^{-1}\left(\frac{x^2+y^2}{x+y}\right)$ then $x \frac{\partial u}{\partial x}+y \frac{\partial u}{\partial y}$ is equal to:

With increasing principal quantum number,the energy difference between adjacent energy levels in $H$ atom

$A$ prism of refractive index $\mu$ and angle $A$ is placed in the minimum deviation position. If the angle of minimum deviation is $A$, then the value of $A$ in terms of $\mu$ is :

The correct order of acidic strength of the major products formed in the given reactions is:
$A.$ $PhNH_2$ $\xrightarrow[\substack{\text{(2) } CuCN \\ \text{(3) } H_3O^{+} / \Delta}]{\text{(1) } NaNO_2 + HCl \left( < 5^{\circ} C \right)} [A]$
$B.$ $CH_3CH_2CHO \xrightarrow[\Delta]{\left[ Ag \left( NH_3\right)_2\right]^{+}, OH^{-}} [B]$
$C.$ $CH_4 + O_2 \xrightarrow[\text{(ii) } Na_2Cr_2O_7 / H^{+}]{\text{(i) } Mo_2O_3} [C]$
$D.$ $PhCH_2MgBr + CO_2 \xrightarrow[H_3O^{+}]{\text{Dry ether}} [D]$
Choose the correct answer from the options given below: