Study the following series.
N 8 U F 5 M D 1 B J C Z X $ I V H 3 % P
Find what should come in place of the question mark(?)
8M , ? , M1 , 1B
There is a gap of 1 between the first characters of each of the given pair. The second character of each pair is decreasingly moving one position to the right of the first character.