This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
All of the following are true about Chlamydia except- 
Select and explain. 
A. Gram positive, B. Causes trachoma, C. Causative organism of psittacosis, D. Are also called basophilic viruses
A: Gram positive
Answer: A: Gram positive 
Explanation: None