Problem: How does the sentence end?

Maria had bad eyes and needed glasses but Katrina did not. 
OPTIONS:
- Maria went to the ophthalmologist.
- Katrina went to the ophthalmologist.
Answer: Maria went to the ophthalmologist.

Problem: How does the sentence end?

Mary could not wash the hair of her dog cleanly with the shampoo because the 
OPTIONS:
- hair is too thick.
- shampoo is too thick.
Answer: hair is too thick.

Problem: How does the sentence end?

Phil went to the neighborhood store for an ordinary battery and an unusual plug for his electronic device, and he special ordered the 
OPTIONS:
- plug because it is proprietary.
- battery because it is proprietary.
Answer: plug because it is proprietary.

Problem: How does the sentence end?

I don't like corn as much as I like broccoli, unlike most people, because to me the 
OPTIONS:
- corn is flavorless.
- broccoli is flavorless.
Answer:
corn is flavorless.