I am an American citizen born and raised. I recently assisted my good friend in applying for a B2 Non Immigration Visa to come to the US and visit me. She is originally from Nigeria but currently a permanent resident working and living in Doha, Qatar. We filled out the DS-160 properly and to the best of our knowledge, paid the for the interview, and during the interview she was asked 3 questions and immediately denied. I would love to know the reason why she was denied and what I can do in order for her not to get denied again. Thank you in advance