Historian: Leibniz, the seventeenth century philosopher, published his version of calculus before Newton did. But then Newton revealed his private notebooks, which showed he had been using these ideas for at least a decade before Leibniz's publication. Newton also claimed that he had disclosed these ideas to Leibniz in a letter shortly before Leibniz's publication. Yet close examination of the letter shows that Newton's few cryptic remarks did not reveal anything important about calculus. Thus, Leibniz and Newton each independently discovered calculus.
Which one of the following is an assumption on which the argument is based?
(A) Leibniz
did not tell anyone about calculus prior to publishing his version if it. - WRONG. It's about either of them independently discovering calculus and not about telling it anyone which does not impacts or helps us know whether they did so independently.
(B) No
third person independently discovered calculus prior to Newton and Leibniz. - WRONG. 2nd best choice for me. If so even then we need further assumptions to be made for it to be the right choice. Not a necessary assumption.
(C) Newton
believed that Leibniz was able to learn something important about calculus from his letter to him. - WRONG. irrelevant.
(D) Neither Newton nor Leibniz
knew that the other had developed a version of calculus prior to Leibniz's publication. - WRONG. Disputing the passage.
(E)
Neither Leibniz nor Newton
learned crucial details about calculus from some third source. - CORRECT. If they did so then it breaks the passage.
Answer E.