Which leader of the Scientific Revolution in France developed the mathematical system of Cartesian coordinates? A. Nicholas Copernicus B. Ptolemy C. Francis Bacon D. René Descartes

The correct answer is D René Descartes.

The name Cartesian Coordinates is taken from the Latin form of his name "Cartesius".

Note that Copernicus was Polish, Ptolemy was Egyptian, and Francis Bacon was English, so of the four names Descartes is also the only Frenchman!