Answer: b. Chlamydophila pneumoniae
Step-by-step explanation:
Chlamydophila pneumoniae is a species of Chlamydia. It is an obligate bacterium. It infects the humans and is responsible for the cause of disease pneumonia. This bacteria is undetected by gram staining. It is associated with the cause of symptoms like fever and shivering. It gives positive results for the cold agglutination test.