Question

read the excerpt from \what to the slave is the fourth of july?\
when the dogs in your streets, when the fowls of the air, when the cattle on your hills, when the fish of the sea, and the reptiles that crawl, shall be unable to distinguish the slave from a brute, then will i argue with you that the slave is a man!
what effect does the repetition of the word \when\ have?
the repetition gives the excerpt a philosophical quality.
the repetition distracts readers from douglasss original point.
the repetition clarifies the time in which the speech was delivered.
the repetition reinforces douglasss incredulity at the oppositions attitudes.

Explanation:

Repetition of "when" emphasizes a series of extreme, unlikely scenarios (animals confusing slaves with brutes). This highlights Douglass's disbelief (incredulity) at those who dehumanize slaves (opposition's attitudes). It's not about philosophy (no deep abstract reasoning focus), doesn't distract (strengthens his point), and time clarification (of speech delivery) isn't the aim.

Answer:

The repetition reinforces Douglass's incredulity at the opposition's attitudes.