The correct answer is C. CO(g) + H2(g).
Syngas is a mixture of carbon monoxide and hydrogen gases. It is produced by the partial oxidation of hydrocarbons, such as natural gas, coal, or biomass. Syngas is a versatile fuel that can be used to generate electricity, produce chemicals, and power vehicles.
Option A is incorrect because it is a reaction of carbon and water, not carbon monoxide and water.
Option B is incorrect because it is a reaction of carbon monoxide and water, not carbon monoxide and hydrogen.
Option D is incorrect because it is a reaction of nitrogen dioxide and hydrogen, not carbon monoxide and hydrogen.