Business Visa - B1

I went to the consulate on 10/08/15 to apply for a b1 visa. This was the Q and A
By the way i am a student studying in another foreign country and my friend had gone the previous week and he was issued with a Visa and he had also prepared me on how to handle the Interview.

By the way i was the first on in the queue so i was a bit tense however i answered the question like i had practiced.

VO - Good Morning
Me - Good morning Sir

VO - What are you doing in this country
Me - I am a student and i am also working at (So so)

VO - When are you completing your studies
Me - In December Sir - I am doing my Thesis now

VO - Why do you want to travel to the US
Me - To attend a Conference

VO - Whats the name of the Conference
Me - XYZ (I mentioned)

VO - What is it about
Me - ABC (I mentioned)

VO - Do you have any family in the US
Me - NO

VO - How many days do you want to go to the US
Me - 4 days

VO - When is that
Me - from the 17-20 August

VO - Where is your family
Me - In my home country (ZZZ)

VO - Are you married
Me - NO

VO - Do you own a property here like a house or a car
Me - NO

VO - Im sorry you do not qualify for a US Visa (As he signed the 214b form)
Me - Thank you - and i collected my passport and left

What should i have done differently?