Final answer:
The use of parallel structure allows Kennedy to emphasize key points in his speech.
Step-by-step explanation:
The correct answer is B) The use of parallel structure allows Kennedy to emphasize key points in his speech.
Parallelism is the use of similar or equivalent constructions of phrases or clauses to emphasize an idea. In this excerpt from President Kennedy's speech, the use of parallel structure allows him to emphasize the absence of strife, prejudice, and national conflict in outer space. By repeating the same structure with each element, Kennedy highlights the significance of these factors in the context of outer space.
For example, instead of saying 'There is no conflict in outer space,' Kennedy uses parallel structure to say 'There is no strife, no prejudice, no national conflict.' This repetition of the phrase 'no [something]' creates a powerful impact and draws attention to the absence of these negative aspects in outer space.