K, L, M, N, O and P are six doctors. Each of them is required to present a paper on AIDS in a symposium. Three papers will be presented in the morning session before the lunch break and the other three will be presented in the afternoon session, subject to the following conditions.
(i) L’s presentation must immediately precede M’s presentation. Their presentations cannot be separated by the lunch break.
(ii) N must be either the first or the last in the order of presenters.
If P and O are fifth and sixth, respectively, in the order, which of the following must be true?