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': 'Clostridium tetani is \nSelect and explain. \nA. Gram positive bacilli, B. Gram negative bacilli, C. Gram positive cocci, D. Gram negative cocci', 'role': 'user'}, {'content': "Answer: A \nExplanation: Clostridium tetani is a gram-positive, slender bacillus. It occurs singly and occasionally in chains. The spores are spherical, terminal and bulging, giving the bacillus the characteristic 'drumstick' appearance. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 264", 'role': 'assistant'}]