This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'Medusa head appearance is a feature of \nSelect and explain. \nA. Bacillus subtilis, B. Bacillus stearothermophilus, C. Bacillus cereus, D. Bacillus anthracis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Bacillus anthracis:When grown on blood agar plates, the organisms produce nonhemolytic gray to white, tenacious colonies with a rough texture and a ground-glass appearance. Comma-shaped outgrowths (Medusa head, "curled hair") may project from the colony.Reference: Jawetz, Melnick, & Adelberg\'s Medical Microbiology; 27th edition; Chapter 11; Spore-Forming Gram-Positive Bacilli: Bacillus and Clostridium Species', 'role': 'assistant'}]