please answer the question n the picture

Answer:
Choice C / 3
Step-by-step explanation:
At 298 K and 101.3 kPa, [tex]H_2O_{(g)}[/tex] is formed from its elements in the equation:
[tex]2H_2+O_2=2H_2O[/tex]
The other choices, however, are not formed by their singular elements, so they cannot be the answers.
Hope this helps!