It would be C because a conjunction can stand alone
I think the correct answer would be C. The best summary of the text "Save the Coral Reefs" would be
Construction along the coasts, overfishing, and bleaching have seriously damaged the world’s coral reefs. Since reefs are a very important part of the ocean’s ecosystem, their destruction has a devastating environmental impact, and we must work to protect them.
Coral reefs are known to be very fragile which are made of limestone. People who would build coastal regions and those who overfish should be stopped as these activities ruin and damage the corals which would ruin the habitat of the fishes and other aquatic organisms.
School starts in a week so Aubrey and her grandmother go "back to school" shopping. Aubrey is not excited for school because she will not know anybody other than Bridget. Her and Bridget spend the last few days of summer playing outside. The first day of school is actually on Aubrey's little sister's birthday which makes it even worst. After the day is over Aubrey actually likes her new school.
Hope that helps
