First sentence:
"I read his biography in class yesterday, he had a unstable life."
Second sentence:
"The excerpt in the novel was detail oriented."
Probably cardiovascular fitness. Hope this helps ;)
Answer:
It would most likely be the research study.
Explanation:
The study was done with research, while with the people's feelings, that is just an opinion, and the family vacation package is not really a credible source.
