The answers to the question above would be the following ones:
A) The rhetorical device used here is repetition. President John F. Kennedy has chosen to repeat the same structures over and over again. We choose to go to the moon. We choose to go to the moon in this decade (...) not because they are easy, but because they are hard, because that goal will serve (...)".
B) The rhetorical device used here is satire. Satire is the use of humour, exaggeration, or ridicule to expose and criticize people's stupidity, particularly in the context of politics.
C) The rhetorical device used here is rhetorical question. Rhetorical questions are asked in order to make a statement. They do not expect any answer. Douglass believes that the wrongfulness of slavery is an issue that he expects everyone to be concerned with.