You are answering a USMLE-style medical question. Question: A 15-year-old woman presents with fever, altered mental status and a petechial rash on her lower extremities and back since yesterday evening. She also says she has been nauseous for the past 3 hours and has vomited twice. The patient mentions she has had heavy menstrual bleeding for the past few days. Her blood pressure is 95/80 mm Hg and her temperature is 40.0°C (104.0°F). On physical examination, the patient appears diaphoretic. A pelvic examination reveals a tampon in her vagina. Binding and activation of which of the following T cell receptors is responsible for this patient’s most likely condition? Options: A) B7 receptor B) Variable β-sequence of the T cell receptor C) CD3 D) IgCAM Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.