[Q]: How does the sentence end?

Kyle was always playing football lighter and easier than Derrick because 

[A]: Derrick was very competitive.


[Q]: How does the sentence end?

Christine told Tanya to keep practicing her instrument every day, because 

[A]: Tanya is her student.


[Q]: How does the sentence end?

Joel did all the shopping for Michael because 

[A]:
Joel had extensive knowledge of local deals and sales.