Did thomas jefferson make the 2 dollar bill?

What would lead a historian to consider two events to have a relationship of correlation rather than causation

Which of the following statements describes the philosophy of thomas hobbes? democracy is necessary for a country to succeed. b. a country needs a ruler with absolute power to succeed. c. people have natural rights to life, to be free and to own property. d. a country needs no rulers or government to be safe and successful.

Why did china build the great wall of china?