What methods can be used to measure a person's blood alcohol concentration (BAC)?

The measurement of a person's blood alcohol concentration (BAC) can be accurately conducted through several methods, each providing valuable information regarding alcohol levels in the body. Breathalyzers are commonly used because they provide quick, non-invasive assessments of BAC through breath samples. These devices analyze the amount of alcohol present in the breath and use it to estimate the alcohol level in the bloodstream.

Blood tests are considered one of the most accurate methods. They directly measure the percentage of alcohol in the bloodstream, making them a reliable choice for detecting BAC. Urine tests can also be utilized to measure alcohol concentration, although they can sometimes be less precise than blood tests, as alcohol can remain in urine longer than it is present in the blood.

Therefore, the correct answer encompasses all three methods: breathalysers, blood tests, and urine tests, as they are all valid approaches for determining an individual's BAC. This combination allows for comprehensive measurement under varying circumstances.