The correct answer to this question is c. scientific methods. If an issue is socially controversial, this will provide the best objective information. Advertising wouldn't because it is biased to one product. School teachers will have their own opinions, and rumors are not based on facts. Scientific methods, however, are based on facts and investigations so it will provide an objective information. Thank you for posting your question. I hope that this answer helped you. Let me know if you need more help.
If you mean how, then Jesus is the son of God. He does not really help you to know about God but he is our Lord and Savior as he has sacrificed himself.