4th/10 on K 20yd line, snap is botched, punter K80 recovers and;
a) scrambles to K 15yd line where he throws a complete pass to ineligible K60 where he is immediately tackled at R 45yd line
b) scrambles K80 scrambles to K 31yd line throws a complete pass to eligible K86 where he is immediately tackled at R 45yd line
c) scrambles to K 10yd line throws a complete pass to eligible K86 where he is immediately tackled at R 45yd line but there is a flag for ineligible receiver down field.
What are the correct enforcement?