Problem: How does the sentence end?

Hunter studied all night and Robert went to a party, instead, and planned on cheating. 
OPTIONS:
- Hunter was the more moral student.
- Robert was the more moral student.
Answer: Hunter was the more moral student.

Problem: How does the sentence end?

The stones that I found at the beach were worse than the rocks I found earlier, because the 
OPTIONS:
- stones were common.
- rocks were common.
Answer: stones were common.

Problem: How does the sentence end?

Tom had to give up paying for his mortgage to pay for his car. The 
OPTIONS:
- mortgage was less expensive.
- car was less expensive.
Answer: car was less expensive.

Problem: How does the sentence end?

The temperature was dropping in the valley but rising on the mountain, making the 
OPTIONS:
- valley so much colder.
- mountain so much colder.
Answer:
valley so much colder.