<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 24-year-old woman of Ashkenazi Jewish descent presents with recurrent bloody diarrhea and abdominal pain. She says she feels well otherwise. Review of systems is significant for a 4 kg weight loss over the past month. Physical examination is significant for multiple aphthous oral ulcers. Colonoscopy reveals a cobblestone pattern of lesions of the mucosa of the intestinal wall involving the sigmoid colon. The patient is informed of the diagnosis and medication to treat her condition is prescribed. On a follow-up visit 6 weeks later, the patient presents with non-productive cough, chest pain, dyspnea on exertion, and worsening oral lesions. A chest radiograph reveals a diffuse interstitial pattern. Which of the following enzymes is inhibited by the medication most likely prescribed for her initial diagnosis?? A: Thymidylate synthase, B: Dihydrofolate reductase, C: Hypoxanthine guanine-phosphoribosyltransferase HGPRT, D: DNA polymerase, E: Thymidine kinase,  <response>: Based on the description of recurrent bloody diarrhea, abdominal pain, weight loss, and colonoscopy findings of cobblestone lesions in the sigmoid colon, the initial diagnosis is likely ulcerative colitis. The medication most commonly used to treat ulcerative colitis is mesalamine 5-aminosalicylic acid. The follow-up symptoms of cough, chest pain, dyspnea, and worsening oral ulcers along with the chest X-ray findings are consistent with mesalamine-induced interstitial lung disease and worsening aphthous stomatitis, which are potential side effects of the medication.Of the enzyme choices, dihydrofolate reductase is inhibited by mesalamine. This enzyme is involved in folate metabolism. Inhibition can lead to folate deficiency, contributing to the oral ulcerations seen in this patient.B: Dihydrofolate reductase 