How could historians us understand why two groups of people are in conflict?
a. historians could explain that the groups live in different areas
b. historians could explain that the groups had once been at war
c. historians could explain that the groups shared the same culture
d. historians could explain that the groups existed hundreds of years ago

B. Historians could explain that the groups had once been at war

Explanation:

Why it is B. is because if two groups are in conflict, something has happened to the two groups that make them have conflict.

War is a good prediction that two groups have conflict.

B. Historians could explain that the groups had once been at war is your answer.

The correct answer is B) Historians could explain that the groups had once been at war.

Historians help us to understand why two groups of people are in conflict because historians could explain that the groups had once been at war.

That is why history is important and we need to learn from it, because as historians say if we do not learn from our past we have the tendency to repeat our previous mistakes. Historians can show and explain why two parties, tribes, individuals or countries are at war and track events to past moments where they had conflicts and wars too.

for this case we have the following equation:

we apply distributive property to the terms within parentheses.

subtracting 2 on both sides of the equation: