Problem: How does the sentence end?

When it came to charities, Kenneth was always volunteering at soup kitchens while Donald never did any charity work because 
OPTIONS:
- Kenneth was very selfless.
- Donald was very selfless.
Answer: Kenneth was very selfless.
sentence: I removed the shower curtain from the tub and replaced it with a shower door. The  OPTIONS:
- curtain was old.
- door was old.
complete: curtain was old.
Tanya earned extra money for college by tutoring Carrie, because 
OPTIONS:
- Tanya was a poor student.
- Carrie was a poor student.
Carrie was a poor student.
Input: Continue writing.

The children in the classroom didn't want to listen to the substitute because the 
OPTIONS:
- classroom was too boring.
- substitute was too boring.

Continued: substitute was too boring.
Story needs to be completed:
Peggy filled the bathtub with hot water and bubbles but not salts, because the 
OPTIONS:
- salts smelled awful.
- bubbles smelled awful.

My choice:
salts smelled awful.
Problem: How does the sentence end?

Samuel made more money cutting hair as a professional stylist than Adam, because 
OPTIONS:
- Samuel charged higher rates.
- Adam charged higher rates.
Answer:
Samuel charged higher rates.