sentence: Erin was a slow learner while Christine was a quick learner, so  OPTIONS:
- Erin was held back a grade.
- Christine was held back a grade.
complete: Erin was held back a grade.

sentence: Jack tried to tow a car with a chain, but the snapped. The  OPTIONS:
- chain was too heavy.
- car was too heavy.
complete: car was too heavy.

sentence: Sugar didn't affect Amy like it did Natalie, but it did because  OPTIONS:
- Amy had stable blood sugar levels.
- Natalie had stable blood sugar levels.
complete:
Amy had stable blood sugar levels.