The answer is N2 + 3H2 yields 2NH3. The oxidation-reduction reaction means that there is electrons transfer during the reaction which means that the valence changed.
Answer: A. Cilla Is Correct.
Answer : The most likely happens during this reaction is, Oxidation-reduction
Explanation :
The balanced reaction will be,

In this reaction, neutral iron loses 3 electrons and oxidizes in (+3) state,
and neutral oxygen gains 2 electrons and reduces in (-2) state,
When iron react with oxygen gas to give iron oxide. This process is known as iron rusting. During the reaction, oxidation-reduction process occurs.
Oxidation : It is a type of chemical reaction in which a substance loses its electrons. Or we can say that in oxidation, the oxidation number increases.
Reduction : It is a type of chemical reaction in which a substance gains its electrons. Or we can say that in reduction, the oxidation number decreases.
Hydroxide is the full name of the compound.
Hope this Helped!
;D
Brainliest??