What is anode

Which of the following is a good clinical example of using the principle of convection to transfer heat?

a. Humidifiers with immersion heaters b. Heated, enclosed infant incubators c. Wire-heated pneumotachometers d. Heated ventilator exhalation valves

For a patient breathing in room air, the EMT would estimate the FiO2 to be:

A) 0.15 B) 0.21 C) 0.55 D) 1.00