You Are Approached by an EMR Who Informs You That

You are approached by an EMR who informs you that last week, he was on a call in which a patient with chest pain and a known history of coronary artery disease was not given oxygen by the EMTs. You would reply:

A) "Ironically, it has been shown that oxygen given to a patient with an acceptable pulse oximetry reading can be harmful."
B) "That may have been an oversight given that chest pain is caused by a lack of oxygen-rich blood delivery through the coronary arteries."
C) "Since extra oxygen slows the respiratory rate, it also causes the body to retain CO₂ which is not beneficial for heart patients."
D) "If the patient also had a history of COPD, oxygen was most likely withheld since it would be contraindicated."