Answer: A) The O'Learys were recent immigrants to America from Ireland.
This passage tells the story of a fire. The details it provides are mostly useful to the account, such as the competing theories regarding the reasons for the fire, the identity of the person who released the story, the location, etc. However, the fact that the O'Learys (the family that owned the barn where the fire supposedly originated) were recent immigrants is not relevant to the fire story at all.