My F1 visa interview experience Location: Hyderabad slot: July 3rd 8:30 AM B.Tech GPA: 7.39 Master'

My F1 visa interview experience Location: Hyderabad slot: July 3rd 8:30 AM B.Tech GPA: 7.39 Master's in mechanical engineering at Texas A&M University- kingsville. Me: Good morning sir, VO: Good Morning, how r u ? Me: i am fine. VO: why this University? Me: I want to work under prof. Dr.Mahesh Hosur who is working on porosity studies on electron beam welding and I got excellent feedback from current studies about faculty and research activities in University. VO: when did you completed your undergraduation. Me: I did Bachelor of technology at KL University in the year 2018. VO: what have you been doing since your undergraduation. Me: In order to continue my research work,I need to learn some softwares like Catia and autocad etc. and I prepared for Gre and IELTS after that. VO: what is your undergraduation GPA? Me: I got 7.39 GPA overall. VO: Do you have Backlogs? Me: No, after 2 seconds, I had Backlogs during my 1st, 4th and 5th semester but I cleared them in next attempt. VO: who is sponsoring you? Me: my parents are supporting me and I got an education loan of 18 lakhs from state Bank of India and University provide me with a scholarship of 8,470$. he typed for 2 mins and gave my passport,i20 and 214b. VO said we cannot provide you visa right now.please look into 214b form and reapply.... Me: ok ,thank you sir. I want to know what mistake I done.