When you said we must have self-respect, i wondered how we could have self-respect and remain patient considering the treatment accorded to us through the years.
this excerpt contains an historical allusion to
a. civil rights activists that advocated for equal rights in the united states throughout the 20th century.
b. the discrimination and bigotry faced by african americans throughout history in the united states.
c. robinson’s belief that an end to segregation is impossible to achieve in the united states.
d. robinson’s belief that president eisenhower is responsible for ending segregation in the united states.

This is part of a letter written by a famous African American, Jackie Robinson.

Considering that he talks about having patience, or not having, and the mistreating of "us" as a group, we can discard anything about activists. Generally, and obviously, blacks were not defenders of segregation and the letter doesn't bring up anything directly about the president.

In fact, he is generally speaking about how his ethnic group has been badly treated throughout the years. So the answer is:

B. the discrimination and bigotry faced by African Americans throughout history in the United States.

no, to many things have came in to factor

the alfred thayer mahan award for literary achievement is awarded each year by the navy league of the united states. the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation. presented since 1957, "this award for literary achievement is awarded to a u.s. navy officer, u.s. marine corps officer, enlisted service member, or civilian who has made a notable literary contribution that has advanced the knowledge of the importance of sea power in the united states."[1]