[Q]: How does the sentence end?

Victoria was always ahead on her bills but Elena was not because 

[A]: Victoria knew how to budget.


[Q]: How does the sentence end?

Natalie is tidy and clean, Erin is not therefore 

[A]: Erin probably doesn't make certain her dolls are clean.


[Q]: How does the sentence end?

Elena has a much harder time being healthy than Amy because 

[A]:
Elena struggles with junk food.