The chemo that Sarah had failed, while Monica's was able to work, so 
OPTIONS:
- Sarah ends up living.
- Monica ends up living.
Monica ends up living.

Rebecca paid for Emily's dinner that night because 
OPTIONS:
- Rebecca was the only one that remembered to bring her purse with her.
- Emily was the only one that remembered to bring her purse with her.
Rebecca was the only one that remembered to bring her purse with her.

I failed my math test even though I used a study guide. The 
OPTIONS:
- test was too easy.
- study guide was too easy.
study guide was too easy.