The statement that best exemplifies a strong persuasive claim is the last one - School communications should be sent electronically to conserve paper.
In this sentence, you have your claim that you want to prove, as well as the reason why your claim is correct. The other options are just facts, they are not sentences you would use in order to persuade someone to believe or do something.
C. sally lives with her parents although she could afford her own apartment.
the connecting word is although.
