Erin was much less aggressive than Megan, so 
OPTIONS:
- Erin had to worry about getting in fights.
- Megan had to worry about getting in fights.
Megan had to worry about getting in fights.

Natalie tried to prevent Monica from entering the house because 
OPTIONS:
- Natalie was trying to find the surprise gift.
- Monica was trying to find the surprise gift.
Monica was trying to find the surprise gift.

Betty made more money teaching at their dance class than Sarah because there were more girls in the class of 
OPTIONS:
- Betty .
- Sarah .
Betty .