Carbon Monoxide Poisoning Carbon Monoxide (CO) Is a Poisonous Gas That Has Is

Carbon Monoxide Poisoning
Carbon monoxide (CO) is a poisonous gas that has is odorless, colorless, and tasteless. These qualities make it possible for you to breathe in toxic amounts of carbon monoxide without realizing that you are in danger.
Carbon monoxide is produced when materials that contain carbon, such as wood, coal, gasoline, oil, or natural gas, are burned. If the space where the materials are burned is not ventilated properly, then the carbon monoxide that is released can build to dangerous levels.
Inhaling carbon monoxide causes the gas to build up in your bloodstream. CO molecules displace oxygen in your blood, depriving your heart, brain, and other organs of oxygen. Early signs of carbon monoxide poisoning include flu-like symptoms, such as dizziness, drowsiness, headache, blurred vision, nausea, and vomiting. Prolonged exposure to large amounts of CO can lead to unconsciousness, irreversible heart, lung, or brain damage, and death.
People who are most at risk of carbon monoxide poisoning include pregnant women, young children, the elderly, and people with serious heart or lung conditions. To prevent carbon monoxide poisoning, people should make sure that places where carbon-containing materials are burned are properly ventilated. Carbon monoxide detectors should also be present in homes, garages, and workspaces.
Which is an example of opinion, rather than factual evidence?

A) It is possible to breathe in carbon monoxide without realizing right away.
B) Pregnant women and young people are most at risk of carbon monoxide poisoning.
C) Carbon monoxide detectors should be present in offices.
D) Carbon monoxide is dangerous because it can be life-threatening.