Which row shows elements in order of increasing first ionisation energy?
K<Mg<P<O\text{K} < \text{Mg} < \text{P} < \text{O}K<Mg<P<O
O<P<Mg<K\text{O} < \text{P} < \text{Mg} < \text{K}O<P<Mg<K
K<O<P<Mg\text{K} < \text{O} < \text{P} < \text{Mg}K<O<P<Mg
Mg<K<O<P\text{Mg} < \text{K} < \text{O} < \text{P}Mg<K<O<P
