Answer:
Shouldn't I?
Explanation:
A question tag can be defined as a very short clause placed at the end of a sentence (statement) which changes it to a question. Some examples of tags used in English language are: can we, can't we, should I, aren't they, shouldn't they, wouldn't it, weren't they, do I, shall we, etc.
In the scenario, the most appropriate or suitable tag to complete the sentence is "Shouldn't I?" meaning the speaker is insinuating that he or she would be surprised if the person comes.
Therefore, the complete sentence is written as; "He might come, but i should be surprised. Shouldn't I?"
