Which of the following pairs of substances on reaction will not evolve ${\mathrm{H}}_2$ gas?

The production of dihydrogen gas via water-gas shift reaction is given below 

$\mathrm{CO} \left(\mathrm{g}\right) + {\mathrm{H}}_2\mathrm{O} \left(\mathrm{g}\right) \underset{\mathrm{catalyst}}{\overset{∆}{\to }} {\mathrm{CO}}_2 \left(\mathrm{g}\right) + {\mathrm{H}}_2 \left(\mathrm{g}\right)$

The ${\mathrm{CO}}_2$ gas is removed by scrubbing with solution of.