Which of these energy rescources has the fewest negative effects on the planet?
a: solar energy
b: nuclear energy
c: hydroelectric energy
d: petroleum

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!

Its led to migrationits led to death 

The correct answer is:   [b]:   "physical systems" .