[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?

Because Neil was younger than Logan,

[A]: Logan completed high school and graduated in an earlier year.

[Q]: How does the sentence end?

Justin didn't enjoy stargazing like Ryan because

[A]:
Ryan lived in an area with clean air.