Problem: How does the sentence end?

Carrie was fixing a fence gate for Rachel for 
OPTIONS:
- Carrie was the other's long time employer.
- Rachel was the other's long time employer.
Answer: Rachel was the other's long time employer.

Problem: How does the sentence end?

Benjamin hired Brett to restring and tune his new guitar because 
OPTIONS:
- Benjamin didn't know how to.
- Brett didn't know how to.
Answer: Benjamin didn't know how to.

Problem: How does the sentence end?

Robert had diabetes while Nick did not so 
OPTIONS:
- Robert had a slice of cake for dessert.
- Nick had a slice of cake for dessert.
Answer: Nick had a slice of cake for dessert.

Problem: How does the sentence end?

Rachel went to the store to buy milk for Angela, and 
OPTIONS:
- Rachel stayed home most of the morning.
- Angela stayed home most of the morning.
Answer:
Angela stayed home most of the morning.