In an experimental setup, certain pathogen caused a disease in primates with nasal congestion, sore throat and fever being the common symptoms. The scientists injected an extract from blue-green mold as the first line of action. However, the symptoms did not subside. The possible causative agents of the disease were listed out as follows.
i. a virus   ii. a fungus    iii. a conjugation deficient bacterium    iv. a tapeworm
Choose the correct option from the following that indicate the pathogen.