Answer:
Letters and publications written by Nazi leaders before the Second World War.
Explanation:
This answer is correct because this historian is searching for the motives of these perpetrators, letters and publications can tell their thoughts and conversations.
<span>A. Many people took out risky loans that could only be repaid if stock prices continued to rise. (apex)</span>
The canal was built in order to easily ship grain from the rich farmland in southern China to the capital city in Beijing
