Final answer:
The level of EMS that involves medical training for those who are usually first on the scene of an emergency is 1) EMT-Basic.
Step-by-step explanation:
An EMT-Basic provides basic care, has knowledge of common medical conditions, and can administer certain medications and treatments like oxygen for respiratory problems and epinephrine for allergic reactions. However, they have limited knowledge compared to paramedics.
In contrast, a paramedic undergoes 2-4 years of training, must have extensive knowledge of common medical problems, and is trained to administer a wide variety of emergency drugs. EMT-Intermediate and EMT-Advanced do not represent the level of EMS training for those who are usually first on the scene of an emergency. The correct level of EMS that involves medical training for those who are usually first on the scene of an emergency is 1) EMT-Basic.