F2 rejection planing to apply again

Hello my name is suma and I applied for f2 visa few days back and got rejected. The questionare went in this way.
V.o : Is ur husband working right
Me: No , he worked in past as research assistant. Right now he is voluntering for the project
V.o : Is he working right now( stressed the same question thrice)
Me: No
V.o: how much he earns
Me: 450$
V.o: Are u working
Me: yes, im a dentist
V.o: How much u earn monthly
Me: after a pause (coz i diny get the amount suddenly) 1 and half lakhs
V.o: sorry u r not valid for this visa
She dint mentioned me the reason for my rejection. Now my husband is not having an on campus job and he is fully funded by his parents.
We are confused coz he is gng to get graduated in a month and unable to find an oncampus job. He already applied for opt starts from feb’2017 to feb’2018.
We are unable to sort out things and was not clear in taking any step forward. Having a plan of applying again but, as he dint have a job now we are afraid that it may get rejected again. So thinking of b1 visa. To be frank as Im confused and I got nervous and dint present myself confidently. Please help me out with this. Thank you.

When you said that he is not working, why did you answer $450 as his earning?

I said her about the past earning. Sorry I wasnt clear in my question. Its about the past. She asked me how much he earned in past i said 450$

Is your husband studying in a school that has been in news for wrong reason?

From the questions it looks like they suspect that the school is a diploma mill that gives out CPT from day 1 and encourages students to work and not study.