The most common method of testing an BAC used by law enforcement officers is the breath-testing device which measures alcohol level in breath from lungs.?

The given statement is true. Breath-testing devices, commonly known as breathalyzers, are widely used by law enforcement officers to estimate the Blood Alcohol Content (BAC) of an individual. These devices measure the amount of alcohol present in a person's breath, which is proportional to the alcohol concentration in the bloodstream. By analysing the breath sample, breathalyzers provide a quick and non-invasive method for law enforcement officers to assess potential alcohol impairment.