Hey there!
The correct answer to your question is option C.
When taking a patient's oral temperature, leave the thermometer in his or her mouth for 1-3 minutes.
Leaving that thermometer for 0-2 minutes is too short, as it can affect the temperature and not give you an exact or close to an exact temperature.
3-5 minutes would be a bit too long because a thermometer needs a time between short and long to give the right temperature that he/she has.
Hope this helps you.
Have a great day!