if H1b Get denial from Employer C but have approved petition from Employer A or Employer B

[SeekingHelp1]

I had employer A and have H1b petition approval till Aug 2020 (which is not revoked from him till now) and I left my employer A and joined employer B in Feb 2018 from here I have H1B petition approval till Jan 2021.

Now I got a job with Employer C but got H1b petition Approval till Dec 2018 so I am confused whether to join or not.

Question is:  if I joined employer C and file extension somewhere in Oct/Nov 2018, in case if this extension gets rejected,  Will I be able to stay in the USA as my employer A or B any of one if not revoked my previous H1b visa?

Please help me. I am thinking to change this job as current job location is near to my home and convenient though not have any benefit in terms of benefits. 

thousand of thanks in advance to all of you.!!

[JoeF]

An employer is required by law to inform USCIS if a person on H1 doesn't work there anymore.

If that employer wants to hire you back they would have to file (and pay for) a new H1 petition.