[Q]: How does the sentence end?

Rachel was less irritated than Jennifer by the tweeting of the cockatoo, because 

[A]: Jennifer had a headache.


[Q]: How does the sentence end?

The store sold lots of simple rings but only a few elaborate necklaces, probably because the 

[A]: rings were cheaper.


[Q]: How does the sentence end?

The body of Katrina was more worn down than Sarah because 

[A]:
Katrina had a hard life.