Problem: How does the sentence end?

The teacher stated that Craig didn't understand the lessons like Benjamin did, since 
OPTIONS:
- Craig listened to them.
- Benjamin listened to them.
Answer: Benjamin listened to them.
sentence: Brian showed Randy the mint plants he was planting in his garden.   OPTIONS:
- Brian was creative.
- Randy was creative.
complete: Brian was creative.
The ring that I bought my girlfriend was worse than the bracelet that I bought her because the 
OPTIONS:
- ring was more expensive.
- bracelet was more expensive.
bracelet was more expensive.
Input: Continue writing.

Christine pinned the orchid flower to Amy 's lapel, thus 
OPTIONS:
- Christine showed her love to her.
- Amy showed her love to her.

Continued: Christine showed her love to her.
Story needs to be completed:
Grandma made greeting cards for her grand children and had to write in pencil but not pen because the 
OPTIONS:
- pencil was useful.
- pen was useful.

My choice:
pencil was useful.
Problem: How does the sentence end?

Christopher does not have good willpower, Nelson does therefore 
OPTIONS:
- Christopher did not eat cake and was not increased in size.
- Nelson did not eat cake and was not increased in size.
Answer:
Nelson did not eat cake and was not increased in size.