H1B transfer while current petition is in RFE

[Paul_H1B_2017]

Hi folks,

I am working with company B based on the receipt notice. The approval process is pending with RFE. Now i have got a better offer from Company C and it has filed a petition for me mentioning Company B's petition as the most recent petition.

Will i be able to join company C before Company B's petition approval?

What happens to petition filed by C if company B withdraws my petition before approval?

How will the months I worked with company B based on the petition receipt which was withdrawn later, be considered ? Will it be considered as legal work status ?

Thanks in advance for your response.