[" 31.Which one of the following has the lowest ionisation "],[" energy? "],[[" (a) "1s^(2)2s^(2)2p^(6)," (b) "1s^(2)2s^(2)2p^(h)3s^(1)],[" (c) "1s^(2)2s^(2)2p^(5)," (d) "1s^(2)2s^(2)2 mu^(3)]]