<span>the arrangement or disposition of people or things in relation to each other according to a particular sequence, pattern, or method.
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B) The daily work continued; nay, it actually increased;
Something that is happening on a consistent basis. It also gives the feeling that it is work to make it persistent. In option B, the statement "daily work" indicates that something is done daily which supports the idea of persistent. The sentence containing the line "The daily work continued; nay, it actually increased" also includes the description "with an astonishing pertinacity." Pertinacity means persistent determination. The brain failing and life slipping away does not show any persistent determination. Also, the statement that she inquired with acute anxiety does not how any persistent determination.
"Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and the success of liberty." (A) contains a hyperbole.
In literature, a hyperbole is a stylistic exaggeration. It is used to give a dramatic effect to a statement.
Here, the hyperbole is: "pay any price, bear any burden, meet any hardship, support any friend, oppose any foe." There are of course prices that the U.S. are going to refuse to pay, burdens they will not afford to carry, etc., but by exaggerating these commitments, Kennedy sounds more resolute and more persuasive.