<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 70-year-old man presents to a medical clinic reporting blood in his urine and lower abdominal pain for the past few days. He is also concerned about urinary frequency and urgency. He states that he recently completed a cycle of chemotherapy for non-Hodgkin lymphoma. Which medication in the chemotherapy regimen most likely caused his symptoms?? A: Cytarabine, B: Methotrexate, C: Rituximab, D: Cyclophosphamide, E: Prednisone,  <response>: This question is asking about a 70 year old man with hematuria, abdominal pain, urinary frequency and urgency after completing chemotherapy for non-Hodgkin lymphoma. It wants to know which medication in his chemotherapy regimen most likely caused these urinary symptoms. Cytarabine, methotrexate and rituximab are antimetabolitesantibodies used in chemotherapy that do not commonly cause urinary side effects. Cyclophosphamide is an alkylating agent used in chemotherapy that can cause hemorrhagic cystitis, resulting in hematuria, dysuria, frequency and urgency. Prednisone is a corticosteroid sometimes used in chemotherapy regimens but does not cause these types of urinary side effects.Therefore, the medication most likely causing his symptoms is cyclophosphamide.D: Cyclophosphamide 