Answer:
The best answer choice for the question: How does the simile in the line "The words leapt like a leaping sword" in stanza 4 affect the poem?, would be: It brings to life the energetic effect these words have on the sailors.
Explanation:
This poem titled "Columbus" and authored by Joaquin Miller, was published in an American Anthology, 1787-1900. It narrates the events experienced by Christopher Columbus and his crew as they were sailing the seas and how Columbus has to use words to maintain the faith of the crew as they face more hardships than success in their voyage.
In stanza 4, as the faith of the crew dimishes more and more, and the difficulties increase, to the point that even the mate starts to question the decisions their Admiral, Columbus, is making. All Columbus does is use the same words after every reflection: "Sail on, Sail on".
When finally in the stanza, they use the simile "the words leap like a leaping sword" what the author is doing is using the idea of a sword that suddenly rises with energy, to show that Columbus wishes to encourage his crew and keep up their faith. These words, in fact, have the desired effect.