Excerpt from: i have a dream
martin luther king, jr.

3 but one hundred years later, the negro still is not free. one hundred years later, the life of the negro is still sadly crippled by the manacles of segregation and the chains of discrimination. one hundred years later, the negro lives on a lonely island of poverty in the midst of a vast ocean of material prosperity. one hundred years later, the negro is still languishing in the corners of american society and finds himself an exile in his own land. so we have come here today to dramatize a shameful condition.

one hundred years later, the negro lives on a lonely island of poverty in the midst of a vast ocean of material prosperity.

what is the literal meaning of this figurative sentence from the passage?
a) african americans are waiting for someone to rescue them.
b) the ocean of prosperity contains an island for african americans.
c) some african americans live on an island in the middle of the ocean.
d) poverty isolates african americans from the mainstream of american society.