The expression of the most probable speed of gaseous molecules is

Solution:

The most likely speed is that, which accompanies the crest of the curve and major fraction of the gas molecules possess this speed.

The expression for the most probable speed of gaseous molecules is $\sqrt{2{\mathrm{k}}_{\mathrm{B}}\mathrm{T}/\mathrm{m}}$

Where,

m is the molar mass of the substance, expressed in kilograms

T is the temperature

${\mathrm{K}}_{\mathrm{B}}$ is the kinetic energy of the molecule

Hence, the correct option is B