For the reaction  ${\mathrm{N}}_2\left(\mathrm{g}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)\rightleftharpoons 2{\mathrm{NH}}_3\left(\mathrm{g}\right)+93.6\mathrm{kJ}$ the amount (i.e. number of moles) of ${\mathrm{H}}_2$, in the system at equilibrium will increase if

For the reaction  ${\mathrm{N}}_2\left(\mathrm{g}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)\rightleftharpoons 2{\mathrm{NH}}_3\left(\mathrm{g}\right)+93.6\mathrm{kJ}$ the amount (i.e. number of moles) of ${\mathrm{H}}_2$, in the system at equilibrium will increase if the volume is increased

Given that there are more moles of products in this scenario, the reaction will shift to the right and create more moles of products since an increase in volume favors the direction that produces the most moles of gas.

Hence option B is correct