Which intergroup relation displays the least tolerance?
segregation
assimilation
genocide
expulsion

  Genocide.

Explanation:

  An intergroup relation refers to an interaction between individuals of different social groups and between the groups each one represent.

  Genocide is the one that displays the least tolerance because it is intentional action to destroy a certain group of people defined as an ethnic, racial, religious, or social group.

  I hope this answer helps you.

think its caste system

explanation:

answer; i do believe that its(gestation,suction-aspiration or vacuum aspiration;