Fear, due to the way the nazi powers put down any other cell or regime that could or would counter them.
I know for sure that it is the first and second one but i think the last answer will be your number 3.
Answer:
Discovery of Calculus
Explanation:
In 1665, he discovered the generalised binomial theorem and began to develop a mathematical theory that later became infinitesimal calculus. Soon after Newton had obtained his degree in August 1665, the University closed down as a precaution against the Great Plague of London.