D is the answer because the all had the right to be informed, the right to be heard, and the right to safety.
The correct answer is: "He developed mathematical principles"
René Descartes (1596 – 1650) was a French philosopher, mathematician, and scientist who lived more than 20 years in the Dutch Republic and was one of the main figures of the Dutch Golden Age.
His great influence in mathematics has been his major contribution to the Scientific Revolution, although his work in philosophy is outstanding too. He developed the the Cartesian system of coordinates. He is considered the father of analytical geometry, which connects both algebra and geometry and which has been used in the development of infinitesimal analysis and calculus .
The answer is a. The Civil Rights Act of 1968.