Which guideline historians place arguments in historical context?

a.)historians should assume that people have always thought the same way throughout time.
b.)historians shouldn’t project modern ideas onto the societies that they are studying.
c.)historians should use older versions of technology to find the sources they need.
d.)historians shouldn’t trace how ideas have changed in different eras.

the three roles stated in the dialogue develop the siblings' personalities.

lloyd's personality looks like a trademarketer

dana's personality is afraid from lloyd's behavior and the oldest sister is a decided person who tries to solve any conflict

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)