The answer is A just took the test :)))
Churchill asks a rhetorical question so that he can then express what he sees as the goal that must be shared by all free nations: the security, safety, and freedom of everyone in the entire world.
A paradox is a literary device that uses two opposing thoughts which may appear senseless, but turns out that it contains a kind of truth in it. A consonance is also a literary device by the repetition of consonant sounds within sentences, phrases or poems. From the given question above, the line that contains both paradox and consonance is option D: At least to know the worst is sweet.
Examples are comma, colon, semi-colon, Dash, parentheses,