Problem: How does the sentence end?

It was necessary for Benjamin to write a note to remind themselves to do their homework but not for Christopher because 
OPTIONS:
- Benjamin had a brilliant  memory.
- Christopher had a brilliant  memory.
Answer: Christopher had a brilliant  memory.
sentence: In preparation for dinner the cook had to rinse the vegetables and not the fruits because the  OPTIONS:
- vegetables were dirty.
- fruits were dirty.
complete: vegetables were dirty.
When deciding which calendar to buy, Samuel chose a small one for Craig, because that is what 
OPTIONS:
- Samuel knows he prefers.
- Craig knows he prefers.
Samuel knows he prefers.
Input: Continue writing.

I like working on the old operating systems over the new operating systems because the 
OPTIONS:
- new operating systems are less complicated.
- old operating systems are less complicated.

Continued: old operating systems are less complicated.
Story needs to be completed:
Concerned the food would cause stains, the woman put an apron over her shirt, because the 
OPTIONS:
- apron was disposable.
- shirt was disposable.

My choice:
apron was disposable.
Problem: How does the sentence end?

Adam chose wood over stone to build the house because the 
OPTIONS:
- wood would make the property less valuable.
- stone would make the property less valuable.
Answer:
stone would make the property less valuable.