"Mawkish" describes something excessively and falsely sentimental, sickly sweet in an emotional sense, often used to criticize writing, films, or speech that overdoes sentiment. The question asks for the closest match to this sense.
"Maudlin" is the word that matches mawkish's sense of excessive, sickly sentimentality.
Let's summarize:
So the correct answer is "Maudlin."
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?