Final answer:
The main effect of the phrases "the whole room spoke of the movement" and "spelled out on our walls" is to show that the living room's contents tell a vivid story of the protests, hence option D is correct.
Step-by-step explanation:
In the passage adapted from Kekla Magoon's 'The Rock and the River' set in 1968, the phrases "the whole room spoke of the movement" and "spelled out on our walls" serve to illustrate the extent to which the civil rights movement permeates the narrator's home life.
This figurative language emphasizes that the signs of activism and the struggle for equality are omnipresent in their living environment, making the cause deeply integrated into their daily existence. The main effect of these phrases is to show that the contents of the living room convey a vivid story of the protests and the commitment of the family to the movement, rather than being literal descriptions of noise or writing on the walls. Therefore, option D is the correct answer.