Answer:
The statement that best explains why the parallelism used in this excerpt is effective is B. It stresses the importance of continuing the fight.
Step-by-step explanation:
The parallel structure of "we shall fight" followed by different locations emphasizes the determination and persistence of the British Empire and the French Republic to continue the fight against Nazi Germany, no matter where it may take place. The repetition of this phrase helps to reinforce the message that surrender is not an option and that they will do whatever it takes to defend their nations. Therefore, the parallelism used in this excerpt is effective in stressing the importance of continuing the fight.