<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 30-year-old woman comes to the physician because of a 1-month history of intermittent abdominal pain, flatulence, and watery diarrhea. The episodes typically occur 23 hours after meals, particularly following ingestion of ice cream, cheese, and pizza. She is administered 50 g of lactose orally. Which of the following changes is most likely to be observed in this patient?? A: Decreased urinary D-xylose concentration, B: Increased serum glucose concentration, C: Increased stool osmotic gap, D: Decreased fecal fat content, E: Decreased breath hydrogen content,  <response>: This question is asking about the expected findings in a patient with lactose intolerance after a lactose tolerance test. The patients symptoms of abdominal pain, flatulence and diarrhea after ingestion of dairy products are classic for lactose intolerance. In lactose intolerance, there is a deficiency of lactase enzyme which breaks down lactose. When given lactose orally, the undigested lactose travels to the colon where it is fermented by colonic bacteria, producing gas, diarrhea, abdominal pain and bloating. This results in an increased stool osmotic gap and increased breath hydrogen content from the bacterial fermentation. The other options would not be expected findings.C: Increased stool osmotic gap 