In the study of history the available documents for studying a certain period is unchanging over time.
Option: B
Explanation:
History is the study of events and phenomena over space and time. Space means where the particular incident is taking place. Time means the period of occurrence of particular event. A certain period suppose the period of sultanate or mughal empire requires some documents, records to be studied in detail.
And these available documents, records can never be changed over time. History is study of things over changing space and time. Archaeological evidences also keep some valid documents for studying historical events.
The correct answer is option C: someone diagnosed with smallpox.
The person that would have been most grateful for the work of 19th-century scientist Edward Jenner, would be someone diagnosed with smallpox because Jenner was who discovered the first vaccine against the smallpox virus. Moreover, this disease that was widely spread in the 18th century and killed many people.
No i would not because no one would want to sell us there goods. it would not benfit because we would loose profit.
The correct answer to this is Natural Resources. <span>In the mid to late 19th century, natural resources were heavily exploited, especially in the West. Land speculators and developers took over large tracts of forests and grazing land. Acreage important to waterpower was seized by private concerns.
Hope this helps :)</span>