Cual es el elemnto central de un estado

Ithink the answer to that would be b):

Nation of conflicting ethnic groups

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!

The answer is filtering so c