This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
Corynebacterium diphtheria is 
Select and explain. 
A. Gram-positive cocci, B. Gram-positive bacilli, C. Gram-negative cocci, D. Gram-negative bacilli
B: Gram-positive bacilli
Answer: B: Gram-positive bacilli 
Explanation: Ref: Harrisons 19th ed. pg. 978* C. diphtheriae is a Gram-positive bacillus that is unencapsulated, nonmotile, and nonsporulating.* The bacteria have a characteristic club-shaped bacillary appearance and typically form clusters of parallel rays, or palisades, that are referred to as "Chinese characters"