Answer:
No net change in reaction occurs in this nucleophilic acyl subtitution reaction
Explanation:
Sodium ethoxide in ethanol gives nucleophilic acyl substitution reaction with ethyl-2-methylpropanoate.
Here ethoxide group replaces an ethoxide group from ester through addition-ellimination pathway.
So, ultimately, the product of this reaction is identical with reactant i.e. ethyl-2-methylpropanoate is reproduced.
Hence one might observe no change during reaction as product and reactant of this reaction are same.
Mechanistic pathway has been shown below.
The answer is A (The ability to react with oxygen)