Problem: How does the sentence end?

Joe found a cloth to clean brass with vinegar to get out the rust but the 
OPTIONS:
- rust was too weak.
- vinegar was too weak.
Answer: vinegar was too weak.

Problem: How does the sentence end?

I like to play with the golf ball rather than a tennis ball as the 
OPTIONS:
- golf ball fits in my fist.
- tennis ball fits in my fist.
Answer: golf ball fits in my fist.

Problem: How does the sentence end?

Patricia owned less fish than Cynthia did because 
OPTIONS:
- Patricia had a bigger sized aquarium at home.
- Cynthia had a bigger sized aquarium at home.
Answer: Cynthia had a bigger sized aquarium at home.

Problem: How does the sentence end?

He wanted to go RV camping but she wanted a luxury hotel, since the 
OPTIONS:
- RV was so dirty.
- hotel was so dirty.
Answer:
RV was so dirty.