The correct option is D Fifth
Given, P's presentation must immediately follow N's presentation.
So, N will be the first presenter and P is second.
Now, L's presentation must immediately precede M's presentation and their presentations cannot be separated by the lunch break. So, L and M will give their presentation at 4th and 5th place or at 5th and 6th place.
Since sixth is not mentioned in the given options. Therefore, M's presentation will be at fifth place.
Hence, option (E) is the correct answer.