What is the meaning of the following quote "if i have seen further it is by standing on the shoulders of giants"

Read the excerpt from martin luther king jr.’s “i have a dream” speech. the negro is still languishing in the corners of american society and finds himself an exile in his own land. and so we’ve come here today to dramatize a shameful condition. the emotional connotation of the underlined word king express his a. indecision. b. hopefulness. c. spirituality. d. outrage.