Option C: 'Did Sue resign' is in simple past tense. It relates to the given sentence 'didn't'. ('Didn't' is a contraction of 'did not'.)
Hence option C is correct.
Option A: 'Sue resigned' is not in interrogative form. It presents a statement, not a question. In interrogative form, the verb (auxiliary/helping verb 'did') comes before the subject 'Sue'.
Option B: 'Does Sue resign' is in simple present tense and states a daily habit or routine. But the actions have already happened: 'didn't'.
Option D: 'Has Sue resigned' is in present perfect tense and states an action just happened in the present.
The sentence, though, has already happened in the past.
Hence options A, B and D are wrong.