He and kathy worried about the reach of the department of homeland security, its willingness to contact anyone born in or with a connection to the middle east. so many of their muslim friends had been interviewed, forced to send in documents and hire lawyers. but until now zeitoun had been fortunate. he had had no experience with profiling, hadn’t been suspected of anything by anyone with real authority. there were the occasional looks askance, of course, sneers from people upon hearing his accent. maybe, he thought, this was just one soldier, ignorant or cruel, wanting to stir things up. why does the author include these details?

the author includes this to give more details about what the actions  of the characters  , connection to the    they way they should be acting towards  zeitoun.

but they are not act that way .    

the answer would be c

by adding "Specifically" to the beginning of the sentence

Adding specifically is the best choice because in sentence 2 the author states that students are "suffering various effects of sleep deprivation". Sentence 3 clarifies what those specific effects of sleep deprivation are. So would not be an effective addition as it indicates a cause and effect relationship which is not what is happening from sentence 2 to 3. And could be a good answer, but the words "may even" already connect hallucinations to sentence 3 so it isn't needed to clarify the relationship between 3 and 4. In addition is not an effective solution because the list of effects is not in addition to what was in sentence 2.