<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 34-year-old man presents to the office for evaluation of a lesion on his upper arm that appeared a few months ago and has not healed. A patient appears healthful but has a history of cardiovascular disease. He states that his friend at the industrial ammunition factory where he works told him he should get it looked at. The patient admits to some nausea, vomiting, and diarrhea over the past year, but he states that he feels fine now. On physical examination, the lesion is an erythematous, scaly, ulcerated plaque on the flexor surface of his upper arm. The rest of the exam is within normal limits. What is the most likely diagnosis?? A: Squamous cell carcinoma SCC, B: Actinic keratosis, C: Erysipelas, D: Contact dermatitis, E: Erythema multiforme,  <response>: This is likely a case of squamous cell carcinoma SCC in a patient with occupational exposure to radiation or chemicals. The chronic ulcerated plaque on the arm that is not healing raises suspicion for a malignant process like SCC. The exposure history at an ammunition factory also increases risk for carcinogenic exposures. The systemic symptoms of nausea, vomiting, and diarrhea could be paraneoplastic syndromes from an occult malignancy. SCC is the most likely diagnosis given the chronic non-healing arm lesion and occupational exposure history.A: Squamous cell carcinoma SCC 