Choose the missing terms out of the given alternatives. Z, X, S, I, R, R, ?, ?

The correct answer is A. G, I.

The sequence is a simple alternating repetition of the letters Z, X, S, I, R, R. The first letter of each pair is repeated, and the second letter of each pair is skipped. Therefore, the missing terms are G and I.

Option B is incorrect because J is not a valid letter in the sequence. Option C is incorrect because K is not a valid letter in the sequence. Option D is incorrect because M is not a valid letter in the sequence.