The answers are:
A. It was a time of great prosperity.
D. It stressed the importance of manners.
E. It included established social rules and codes.
F. It emphasized the importance of appearances.
I would say the correct answer is that has an undetermined answer.If a subject has been thoroughly covered, then there is no need for this researcher to do it all over again. If it's impossible to answer, there is no need to try. If it can be answered easily, then it doesn't really require a research. This leaves us with the last option, because a researcher might want to try and determine the answer.
Well I can’t see the answer to choose from problem is D
"American paleontology got a bad reputation from Cope and Marsh's cutthroat behavior", states J. R. Hill in the article The Bone Wars and it is true because they were worried about fame and who was a better paleontologist and did not worried about science.
In the text this shows when it says:
"The mistakes they made in the rush for glory slowed the progress of paleontology for many years".
"In addition to sabotaje, Cope and Marsh forced their teams to dig up and transport bones quickly. Such speed damaged many specimens, but each man wanted the credit of making the first discoveries of new species".
It describes the types of transportation used by various troops throughout history