No, a preposition is often used to describe where usually following a noun, such as in, on, with, by, and etc.
"But" is a coordinating conjecture. Hope this helps.!
Answer:
C "Hence, more schools should follow the trend of starting later in the morning if they want to see improved test scores, greater attendance numbers, and, most importantly, healthier, happier teens."
Explanation:
I doubted it at first because it sounds too repetitive with sentence 13, but it makes more sense than the other options and relates to the argument and establishes a unified end as it summaries that more schools should have a later start time to help students succeed academically and improve their general wellbeing.
Anyone can say what they want, believe what they want, and no one can stop them
C. The need for more time between classes.
