Problem: How does the sentence end?

The song took longer to sing than the ballad because the 
OPTIONS:
- song was more words.
- ballad was more words.
Answer: song was more words.

Problem: How does the sentence end?

Kenneth screamed at Benjamin because 
OPTIONS:
- Kenneth was so upset about the bad experience at the restaurant.
- Benjamin was so upset about the bad experience at the restaurant.
Answer: Kenneth was so upset about the bad experience at the restaurant.

Problem: How does the sentence end?

I couldn't pass my math class even though I hired a private tutor. I guess the 
OPTIONS:
- class was too inept.
- tutor was too inept.
Answer: tutor was too inept.

Problem: How does the sentence end?

The spots were still visible on the shirt but not on the pants, since the 
OPTIONS:
- shirt had been dirtied .
- pants had been dirtied .
Answer:
shirt had been dirtied .