Problem: How does the sentence end?

I was very scared to put the new machine on the desk, because the 
OPTIONS:
- machine was weak.
- desk was weak.
Answer: desk was weak.

Problem: How does the sentence end?

The rod is better than the pipe for fitting in tight spaces because the 
OPTIONS:
- rod is thinner.
- pipe is thinner.
Answer: rod is thinner.

Problem: How does the sentence end?

The man chose concrete for his driveway rather than gravel although the 
OPTIONS:
- concrete was expensive.
- gravel was expensive.
Answer: concrete was expensive.

Problem: How does the sentence end?

Neil got duped by the counterfeit handbags, but Samuel knew the deal was too good to be true, because 
OPTIONS:
- Neil was too trusting.
- Samuel was too trusting.
Answer:
Neil was too trusting.