The equation that represents the water-gas shift reaction is :

Options

1. A${CH}_{4}\left(g\right) + {H}_{2}O\left(g\right)\dfrac{1270K}{Ni}CO\left(g\right) + 3{H}_{2}\left(g\right)$
2. B$2C\left(s\right) + {O}_{2}\left(g\right) + 4{N}_{2}\left(g\right)\overset{1273K}{⟶}2CO\left(g\right) + 4{N}_{2}\left(g\right)$
3. C$C\left(s\right) + {H}_{2}O\left(g\right)\overset{1270K}{⟶}CO\left(g\right) + {H}_{2}\left(g\right)$
4. D$CO\left(g\right) + {H}_{2}O\left(g\right)\mathop{\to}_{catalyst}^{673K}{CO}_{2}\left(g\right) + {H}_{2}\left(g\right)$