Which set of quantum numbers is not allowed?

$\mathrm{n}, \mathrm{l}, {\mathrm{m}}_{\mathrm{l}}, {\mathrm{m}}_{\mathrm{s}}$

The set of quantum numbers is not allowed is $\begin{array}{l}2,\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}2,\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}1,\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}-\frac{1}{2}\end{array}$

There can be no zero for the main quantum number (n). Therefore, the permitted values for n are 1, 2, 3, 4, and so forth. Any integer between 0 and n – 1 can serve as the angular quantum number (l). For instance, if n = 3, l might be one of 0, 1, or 2.

Hence, the option B is correct.