Which sentence correctly uses the semicolon?
it was already late in the evening; and i wanted to go to bed. there was no reason to stay awake, since we knew that the power would not come back on until the morning. it had been a most unpleasant coincidence that the power outage had come when we had guests staying over; the entire house was full. still, most of our guests had been understanding about it; so there was, for the most part, good humor all around. staying on the second floor of the house were uncle john, aunt sally, cousin roger, pete, the twins, and myself. we had it worse than everyone on the first floor, all the windows in all the upstairs rooms were tinted; and there wasn’t enough moonlight in the first place.
a)it was already late in the evening; and i wanted to go to bed.
b) it had been a most unpleasant coincidence that the power outage had come when we had guests staying over; the entire house was full.
c) still, most of our guests had been understanding about it; so there was, for the most part, good humor all around.
d) we had it worse than everyone on the first floor, all the windows in all the upstairs rooms were tinted; and there wasn’t enough moonlight in the first place.

B) It had been a most unpleasant coincidence that the power outage had come when we had guests staying over; the entire house was full.

This is the correct answer because the semicolon is carrying out its function here: to join two independent clauses that are related to each other.

A, C and D are wrong because they all have conjunction following the semicolon: "and" and "so". And semicolons aren't used with conjunctions, as for they both perform the same function: to link two independent clauses. So when trying to connect two independent clauses, we can either use a semicolon or conjunction, not both at the same time.

there on the beach was a struggling turtle.   around its bright green neck was a loop of soda can rings.   in order to the planet, i have made a few changes to my life.   the first change is reducing the number of straws used. the second change was to recycle.   finally, i have worked hard to clean up litter.   it is important to clean our ocean.

you may not think straws have a large impact but they do.   imagine for every straw you sip out of a poor, , adorable turtle is being harmed.   one way i chipped in to is by using metal straws.   these straws are reusable and inexpensive.   another change is simply turning down straws.   by refusing a straw, i’m the turtles one drink at a time.  

however, the ocean just doesn't have turtles.   there are lots of creatures that live there and are harmed by all the litter.   to prevent litter from growing it’s important to recycle.   for me, i have started to buy most goods that are made out of recycled material.   pura vidas, chacos, purses, and too many other items to even count.   plus, when you buy those products they give money to charities.   not only am i the environment, but i’m also feeling better about my self.   finally, i have worked hard to clean up litter.   it is important to clean our ocean.

explanation:

what does the teacher mean