Option 1, C(s) + HzO(g), does not produce syngas. When carbon reacts with water vapor, it forms carbon dioxide (CO2) and hydrogen gas (H2), not syngas.

Option 2, CO(g) + HzO(g), also does not produce syngas. This reaction produces carbon dioxide (CO2) and hydrogen gas (H2), similar to option 1.

Option 3, CO(g) + H2(g), is the correct answer. This combination of carbon monoxide (CO) and hydrogen gas (H2) is what is commonly known as syngas. Syngas is a mixture of carbon monoxide and hydrogen, which can be used as a fuel or as a starting material for various chemical processes.

Option 4, NO2(g) + Hz(g), does not produce syngas. When nitrogen dioxide reacts with hydrogen gas, it forms ammonia (NH3), not syngas.

In summary, option 3, CO(g) + H2(g), is called syngas.