Select the letter that can replace the question mark (?) in the following series. W, Q, ?, H, E, C

N L K M

L

Pattern followed is : Subtract numbers in decreasing order  from each next number . W, Q, ?, H, E, C W - 6 = Q , Q - 5 = L , L - 4 = H , H - 3 = E , E - 2 = C L fits well in series  to follow the pattern . Ans = L