The correct answer is: O, C
The sequence is a simple alternating repetition of the letters Z, S, W, O, T, K, Q, G. The first letter of each pair is repeated, and the second letter of each pair is skipped. Therefore, the next two letters in the sequence are O and C.
Option A is incorrect because N is not a letter in the sequence.
Option B is incorrect because D is not a letter in the sequence.
Option C is correct because O is the first letter of the next pair in the sequence, and C is the second letter of the next pair in the sequence.
Option D is incorrect because O is already in the sequence, and D is not a letter in the sequence.