Answer:
The reason why Stephanie -who does not consume alcohol but was medicated for coughing- had a high reading when she had her preliminary breath test (PBT) is because the medication contained molecules similar to ethanol (option C).
Step-by-step explanation:
Breath alcohol content (BAC) is a measure that is performed through the use of special devices, such as the brethalizer, an analyzer for detecting blood alcohol in drivers. Ethanol is a volatile product that, when found in the blood, is partially eliminated by the airways.
The use of certain types of medications may cause a high reading on the breathalyzer because they contain ethanol. This is likely to have happened to Stephanie who was using a cough medicine -which usually has a low ethanol content- and got a positive reading on the breathalyzer.