Final answer:
The claim that the only accurate way to measure BAC is through counting standard drinks is false; BAC is most accurately measured through blood or breath testing, such as using a Breathalyzer.
Step-by-step explanation:
The statement that the only accurate way to measure BAC is to count standard drinks is false. Blood alcohol concentration (BAC) indicates the level of intoxication and legally, it is often defined as a BAC of greater than 5.4-17.4 mmol/L (25-80 mg/dL or 0.025-0.080%). It can be measured accurately by blood or breath testing. Factors such as age, sex, pre-existing health conditions, and individual differences in metabolism affect BAC levels, making counting standard drinks an unreliable method for determining BAC.
Certain instruments like the Breathalyzer are designed to measure the ethanol concentration in a person's breath, giving an estimate of their BAC. Hence, the Breathalyzer test is considered a standard method for on-the-spot BAC estimation and is widely used by law enforcement.
While keeping track of standard drinks can provide a general gauge of alcohol consumption, it does not provide a precise BAC level due to these individual variations and potential differences in the actual alcohol content of different drinks.