The type of speech it is, is a simile
Detention aims to make a discipline among the students who break rules and policies in school.
It is been said that if a student violates or breaches a policy or rule must be taken for such disciplinary action as it would serve as a consequence for a certain undesirable act. It would be considered that detention instills self-realization that is beneficial to the student's development and learning.
Of the opening sentences that were presented here that strongly engages the reader and provides context to them would be the second one which is "We could have had a worse weekend, but it's awfully hard to beat Bigfoot and bugs."
The first and third one were just not good enough because it exposes the rest of the context to the reader and lets them have the idea of what you are talking about which usually leads to the readers not choosing to continue to read, thus taking out the reader's engagement but still provides context. The last one is better than the first and third, but it spilled the beans when it mentioned the particulars as to what made the weekend bad to worse. The answer is just right. It has the impact that would hook the reader to know more about your weekend and why is Bigfoot and bugs together in your statement. The rain wasn't mentioned which would be ideal to make the story telling take a turn to much worse which would spike up the interest of the reader.
The answer is c. The number of different times zones in the United States