The correct options are
A Voltaire
B Rousseau
C Montesquieu
These were French thinkers who revolutionised the way of thinking and brought in rationality. Voltaire focused on the ideals of equality and humanism, he questioned and ridiculed the clergy. Rousseau introduced the idea that people are sovereign and highlighted the importance of freedom. Montesquieu encouraged the ideas of democracy and the republic and the division of power among three organs of governance.