A historian is interested in learning about the ancient Roman Colosseum, an arena where trained fighters battled one another for spectators'
entertainment. Many gladiators were slaves who were forced to fight to the
death with other people and even wild animals. The historian has a difficult
time understanding how any person would enjoy, or even tolerate, watching
such things.
If the historian wanted to use contextualization to better understand the
Colosseum, which action would he take?

A historian can study ancient Roman culture to learn about attitudes of Roman toward slavery and violence.

Explanation:

The historian has a difficult time understanding how any person would enjoy, or even tolerate, watching such a thing where slaves were forced to fight to the death with other people and even wild animals just for spectators' entertainment.

To better understand the Colosseum, a historian can study ancient Roman culture to learn about the attitudes of Roman toward slavery and violence.

what are local authorities doing to fix the problem

explanation: what are local authorities doing to fix the problem

a historian researching the immigration policies of the early 1900s would expect a source written today,rather than in 1910 to :

( a ) be more interested in objective data and statistics.