Do i Require stamping again with old employer

USA H1B Visa
1

Hello Sir,

I was working with employer A in the US then employer B filed a transfer petition and A also filed a transfer petition.

I came back to India then both got approved and I went on stamping with employer B and got stamped.

But the question is if I want to work with employer A only do i need to get it stamped with employer A again or stamping with employer B is fine even if i want to work with employer A?

Note:Employer A got approval with i94

2

My Question is:
Since i stamped with employer B but wanted to work with employer A can i submit my employer A approval copy at the port of entry?

thanks
krishna