Ahistorian must rely on other social scientists when answering which question?
a. who?
b. when?
c. where?
d. why?

The correct answer here is D - Why. Whilst some of the other possible answers here might need help from other scientists, in that to understand when there may need to be dating methods from a scientist, or to understand where the aid of a geologist might be needed, it is only the why that might require help from other social scientists. For example, anthropologists, sociologists and psychologists might be able to help explain why a society was a certain way.

The total amount of new york is equal to 90*