H1B Extension got RFE , Can i Switch to new employer now?

I filed my H1B extension from employer A(Current Employer) in premium process and received an RFE from USCIS which is a documentation Error from attorney,my I94 expires on August 1st,
Ques 1:-In this situation can i transfer my H1B to employer B , what are the risks?
Ques 2: Or should i wait for the RFE to be answered from the employer A, since it is a documentation error from attorney what is the chance of case getting approved…?
Quest 3:-will my I140 still valid

Fundamentally There is NOTHING called H1 Transfer in the books of USCIS. All petitions are independent and parallel, thus, there is not direct connection between your existing employer H petition Vs another employer filing another H petition for you.
Having said that, please proceed to have any number of other employers who wants to file your H1 petition without being worried about one employer’s petition status(but you must be able to maintain AT LEAST ONE employer’s H1 legal status AT ANY TIME)
Your questions:
Ques 1:-In this situation can i transfer my H1B to employer B , what are the risks?
You can, no risk
Ques 2: Or should i wait for the RFE to be answered from the employer A, since it is a documentation error from attorney what is the chance of case getting approved…?
You dont need to wait
Quest 3:-will my I140 still valid
Yes