Problem: How does the sentence end?

Hunter was unable to explain their behavior while looking Samuel in the eyes, because 
OPTIONS:
- Hunter being cruel.
- Samuel being cruel.
Answer: Samuel being cruel.
sentence: Neil wanted to have visit Dennis from Florida but  OPTIONS:
- Neil couldn't afford to take a vacation right now.
- Dennis couldn't afford to take a vacation right now.
complete: Dennis couldn't afford to take a vacation right now.
The guide referred the kids to the counsellor because the 
OPTIONS:
- guide didn't know the answer.
- counsellor didn't know the answer.
guide didn't know the answer.
Input: Continue writing.

Lonnie put mortar between the bricks with a spatula instead of a trowel, because the 
OPTIONS:
- spatula was efficient.
- trowel was efficient.

Continued: spatula was efficient.
Story needs to be completed:
Sarah was more successful at work than Betty because 
OPTIONS:
- Sarah stayed longer hours at the job.
- Betty stayed longer hours at the job.

My choice:
Sarah stayed longer hours at the job.
Problem: How does the sentence end?

Mark never pays with his debit card and uses the credit card instead, because the 
OPTIONS:
- debit card is more safe.
- credit card is more safe.
Answer:
credit card is more safe.