Which of the following is an example of a bodily fluid that can transmit infection through contact?

Saliva is an example of a bodily fluid that can transmit infections through contact because it contains various pathogens, including bacteria and viruses, which can be spread via droplets or direct contact with mucous membranes. When it comes into contact with another person, particularly through activities like kissing or sharing utensils, it can easily facilitate the transmission of infectious agents.

Contrasting with this, air is not a bodily fluid but a medium that can carry pathogens through aerosolized particles, and it does not directly transmit infections through contact. Temperature is a measure of heat and does not engage in the transmission of infections. Blood pressure is a vital sign indicating the force of blood against the walls of blood vessels and is unrelated to the transmission of infections.