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
Which one of the following statements is true regarding Chlamydia pneumoniae - 
Select and explain. 
A. Fifteen serovars have been identified as human pathogens., B. Mode of transmission is by the airborne bird excreta, C. The Cytoplasmic inclusions present in the sputum specimen are rich in glycogen, D. The group specific antigen is responsible for the production of complement fixing antibodies
D: The group specific antigen is responsible for the production of complement fixing antibodies
Answer: D: The group specific antigen is responsible for the production of complement fixing antibodies 
Explanation: None