Most consistent is the least dispersion in the scores. We have a parameter called Coefficient of Variance which is used to measure relative measure of dispersion between two sets.
Coefficient of Variance(CV) = $\frac{Standard Deviation}{Mean}$
Calculating it for all the four players.
K's CV = 0.167
L's CV = 0.138
M's CV = 0.114
N's CV = 0.329
Larger the value of CV, less consistent the player is.
So the most consistent player is M here
Option C