The correct answer is A) they put more power in the hands of the king.
What French aristocrats did in an effort to keep their privileges was "they put more power in the hands of the king."
The nobles in France were the wealthy and powerful class in French society. They benefitted so much of the relationship they had with the monarchy. For instance, they did not pay taxes. People from the third state, the peasants and poor ones were the ones that paid taxes. These kinds of injustices were the ones that accelerated the French Revolution.
The other options of the question were B) they declared war on the king. C) they left the Catholic Church. D) they organized an elected Parliament.