The answer is letter C.) a newspaper editorial about families who were displaced.
A newspaper editorial refers to the opinion of a leading staff or writer of a newspaper. This would share data on how families were affected by the Great Chicago Fire, through the lens of an educated staff. The other sources presented only speak a small percentage of the families/people affected by the fire.
Thank you for posting your question. I hope you found what you were after. Please feel free to ask me more