Nitrogen
Hydrogen
Oxygen
Carbon dioxide
Answer is Right!
Answer is Wrong!
The correct answer is B. Hydrogen.
When metals react with dilute acids, hydrogen gas is produced. This is because the hydrogen ions in the acid react with the metal to form hydrogen gas and the metal salt. For example, when zinc reacts with hydrochloric acid, the following reaction occurs:
$Zn(s) + 2HCl(aq) \to ZnCl_2(aq) + H_2(g)$
The hydrogen gas is produced at the surface of the metal, and it can be collected by bubbling it through water.
The other options are incorrect. Nitrogen is not produced when metals react with dilute acids. Oxygen is produced when metals react with strong acids, such as nitric acid. Carbon dioxide is not produced when metals react with acids.
I hope this helps! Let me know if you have any other questions.