Which of the following statements is a paradox?
a) “There is no room for the impurities of literature in an essay.” (“The Modern Essay,” Virginia Woolf)

b) “This affair must all be unraveled from within.” (The Mysterious Affair at Styles, Agatha Christie)

c) “Men work together . . . whether they work together or apart.” (“The Tuft of Flowers,” Robert Frost)