How is mononucleosis primarily transmitted?

Mononucleosis is primarily transmitted through respiratory droplets, which is why the correct answer focuses on this mode of transmission. The virus responsible for mononucleosis, commonly the Epstein-Barr Virus (EBV), is mainly spread through saliva, and coughing or sneezing can release these infectious droplets into the air. Close personal contact, such as kissing, is a typical way the virus spreads, which is why respiratory droplet transmission is significant.

Understanding the transmission route is crucial for controlling spread, as it emphasizes the importance of hygiene practices and awareness in social interactions, especially in settings like schools or crowded places. The other choices provided, while they represent different modes of transmission for various diseases, do not apply to mononucleosis. Blood transfusions, contact with contaminated surfaces, and insect bites are not common routes for the transmission of EBV, underlining the uniqueness of respiratory transmission in the spread of this particular illness.