[Q]: How does the sentence end?

Jason excelled at the violin lessons while Logan struggled, because 

[A]: Jason had a gift for music.


[Q]: How does the sentence end?

I used to keep my jack in the garage, but now keep it in the trunk because the 

[A]: trunk is more convenient.


[Q]: How does the sentence end?

Katrina became clingy and upset just before Betty had to leave, because 

[A]:
Betty was their mother.