B2 Visa Rejected of my Family want to reapply...What will be the best time to apply again

Hello,

Me and My husband just applied for tourist visa of my parents and my sibling. My Husband is on H1B and me on H4. he was sponsoring them for all their expenses. Including ticket,there Stay and other expenses to.

My parents had all his document which include.

I134s Copy of H1B Approval Copy of passport (of both of us)Employment Letter Copy of last three bank statements Bank Account verification letter Copy of last three salary Statements Copy of last two years Tax returns.

Question asked to my parents and my school going sibling

Que: What is purpose for visit? Ans: to visit some tourist place and to meet my daughter and son in law

Que: How many children you have?

Ans: Our Daughter stays in USA and other daughter who is doing her study.

Que: Do you have any grandchildren?

Ans: no

Que: (to my sibling) Have you took leave to your school?

Ans: No not yet.

Que: (to my mother) do you work?

Ans: No I am housewife.

Que: Any relatives there in USA?

Ans: No.

Que: On which Visa your son in law is stay in USA?

Ans: H1.

Que: On which Visa your daughter is stay in USA?

Ans: H4.

Que: (to My father) are you doing service ?

Ans: yes.

Que: (to My father) which service you do?

Ans: Insurance agent.

Que: (to my father) Since how long you are doing?

Ans: 7 year back i started.

this are all their questions and they not asked for any document and visa rejected under 214B section. Can you please Suggest what is went wrong in above interview.

Now next time when I am going to apply I am going to Apply just for my mother. What will be the best time and what reason should I present.