Answer:
1. C
2. C
3. C or A, depending on what your teacher prefers
4. B
5. buses
Step-by-step explanation:
Remember, only put apostrophes on the object when it possesses (has) something.
For plural objects, only put one apostrophe and one letter S, like this: puppies' (not puppies's).
Regarding last names ending with the letter S, both S' and S'S are correct; it just depends on what your teacher prefers.
Example: Jones' or Jones's are both correct.
Hope this helps! :)