Answer:
A, The Author's Relationship with her sister.
Explanation:
I assume that it's B, because it focused much on her sister in the passage. The other choices are kind of inrelevant. B, There was no traffic mentioned in the passage, C, It states that there were watches, not warnings, and also, weather is unpredictable, and the author never states anything about that. D, the dangers of ignoring tornado watches, a close second. If it wasn't B, then it was D.