Answer:
The information source that would best help a reader synthesize information with a novel she is reading is a chapter in a history textbook.
Step-by-step explanation:
When we synthesize we collect information from different sources to get to a general conclusion or a new idea or theory about the topic we are reading about, therefore if a person has more context about the time period when the story is set, they will be able to get to better conclusions and understanding of the whole.