if previous visa application rejected what to explain in my case?

[krisbadsg]

i attended for interview in december 2014. i made 2 mistakes in interview.

for both the questions i filled wrongly and tried to rectify till the interview time, but i don't know how?

mistake 1.my brother is staying in usa and in the application i filled " i don't know the present visa status of my brother" but in interview i answered his status as " permanent resident (green card holder)"

mistake 2. for the question who is sponsoring for the trip i filled "self" and at the time of interview i answered " my brother "

now i am applying for USA visa again.

and for the question explain why i have been rejected the visa what should i write in the box,

please help asap

thank you