<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 19-year-old male college student presents to the clinic in the month of January with a 2-day history of watery diarrhea. The patient also complains of weakness, nausea, vomiting and abdominal cramps. He has no significant past medical history. He does not take any medication. He drinks socially on the weekends but does not smoke cigarettes. He recently returned from a cruise with his fraternity brothers. Blood pressure is 11070 mm Hg, heart rate is 104min, respiratory rate is 12min and temperature is 37.7C 99.9F. On physical examination his buccal mucosa is dry. The physician suggests oral rehydration therapy. Which of the following is the most likely causative agent?? A: Norovirus, B: Rotavirus, C: Helicobacter pylori, D: Staphylococcus aureus, E: Enterotoxigenic Escherichia coli,  <response>: This is a clinical case scenario about a 19-year-old male college student presenting with acute watery diarrhea, nausea, vomiting, abdominal cramps and dehydration after returning from a cruise. The key clues are:- Young adult with acute onset watery diarrhea - Nausea, vomiting, abdominal cramps suggests gastroenteritis- Recent travel history - went on a cruise before symptom onset- No significant medical historyBased on the clinical presentation and recent travel history, the most likely diagnosis is acute gastroenteritis caused by a viral pathogen. Cruise ships are well-known sources of outbreaks of norovirus and rotavirus gastroenteritis. Norovirus is the most common cause of acute gastroenteritis in adults. Rotavirus more commonly affects infants and children but can also cause outbreaks in young adults. A: Norovirus 