Problem: How does the sentence end?

The new deck wouldn't fit behind the house because the 
OPTIONS:
- deck was just not long enough.
- house was just not long enough.
Answer: deck was just not long enough.

Problem: How does the sentence end?

You can use both flour and cornstarch to thicken soups, but the 
OPTIONS:
- flour is a less common kitchen ingredient.
- cornstarch is a less common kitchen ingredient.
Answer: cornstarch is a less common kitchen ingredient.

Problem: How does the sentence end?

Geena began doing yoga on the mat instead of the carpet, because the texture of the 
OPTIONS:
- mat gave her less traction.
- carpet gave her less traction.
Answer: carpet gave her less traction.

Problem: How does the sentence end?

Rebecca is not rich but Mary is very much so, and so 
OPTIONS:
- Rebecca goes back home to a hovel and not a mansion.
- Mary goes back home to a hovel and not a mansion.
Answer:
Rebecca goes back home to a hovel and not a mansion.