The interjection in this sentence is Yikes!
Interjections are used to express some emotion, and they often end with an exclamation mark.
Most likely A, to insure safety from terrorist.
In case anyone needs extra confirmation, the correct answer is indeed:
"It helps convey the idea that, during apartheid, many South Africans who disapproved of their government's racist policies did not trust the police to follow the law or to be honest about their actions."
Just took the test and got this right :)
