According to Elijah Anderson, Reading Terminal is a place where diverse groups can come together peacefully because the people who go there are "cosmos" (shorthand for cosmopolitan). According to his observations and interpretations, the dynamic that is largely missing from Reading Terminal is:

a. social status.
b. ethnocentrism
c. regionalization.
d. audience segregation.

b. ethnocentrism

Explanation:

Ethnocentrism is the view of things in which one's group is the center of everything,and others are scaled and rated with reference to it. Each group nouurishes its ownpride and vanity, boasts itself superior,exalts its own divinities and looks with contempt on outsides.

It is basically "Anything ou can do, we can do it better" point of view concerning ethnicity.

According to Elijah Anderson, Reading Terminal is a place where diverse groups can come together peacefully because the people who go there are "cosmos" (shorthand for cosmopolitan). According to his observations and interpretations, the dynamic that is largely missing from Reading Terminal is ethnocentrism.

there is an explationation of this on a site called crash   course world history 1