A BRAIN CRANK TO GET YA BRAIN CRUNK!

Towards the end of this famous speech, Martin Luther King, Jr. uses the phrase "I have a dream" to begin eight straight sentences in a row. This rhetorical repetition is an example of which literary device:

A. Epistrophe
B. Alliteration
C. Extended Metaphor
D. Anaphora

Need a hint? Click the picture!