Of all the most important substances imported into Western Europe from the East after 1480, these three items had the least impact on both population growth and life-expectancy (compared to the one item on the list that did):
Medicine
Salt
Cinnamon
Steel

the answer to this question is the third option. hope this

probally   a few days after there called

your answer would be (b)

i believe it would influence their own way of understanding things. it shall be a foundation where they can draw or start an argument.   historians are also  scientists that  have their tools of analysis and expertise to unlock a variety of difficulties such as relationships of man, origin, politics, economy, and culture. based on facts and understanding on these areas, they may shade light to extract ideas and develop options to validate a hypothesis or debunk it.