The missing character is J.
The sequence is a list of letters that are one letter before the letter that comes after them in the alphabet. Starting with the letter A, the next letter in the sequence is B, then C, and so on. The missing letter is the letter that comes one letter before K, which is J.
A. F is not the missing letter because it is two letters before K.
B. J is the missing letter because it is one letter before K.
C. N is not the missing letter because it is four letters before K.
D. T is not the missing letter because it is six letters before K.