The separation of one group of people from the larger group is called
a. rational basis test.
c. segregation.
b. a strike.
d. naturalization.

Another word for separation is "segregation" and this is in fact the word that is used for the situation when one group of people is separated from another and does not participate in many aspects of the life of the life of majority.

Naturalisation is the process of obtaining a citizenship of a country.

3. i would say one, but one is not prime nor composite.