I think the answer is A. Hope this helps !!
Lung helps in respiration as it acts as a pressure gradient between our body and atmosphere, so if we get only one lung, then the pressure would be very low, and we won't be able to do necessary works, but for survival, it is possible with one lung
Hope this helps!
Answer: i see that you looked it up but there are not any trustful advice. Let me further reasearch this so i can help you out :P
Answer:
noo it is soo it yr Agnosticism
don't afraid
hope it helps