Which line represents the subject's breath flow rate during the test on the printout?

The breath flow rate during the test is represented by the thinner line on the printout. This line denotes the changes in the subject's breath flow as they blow into the Intoxilyzer 9000. The breath flow rate is a critical part of the testing process, as it indicates the strength and consistency of the subject's breath when providing a sample.

The thinner line provides a clear visualization of these fluctuations, which are essential for determining an adequate and valid breath sample. The thicker line may represent other important measurements such as the breath alcohol concentration or calibration data, while the dashed line could indicate a threshold or warning marker. The solid line may represent different parameters that do not specifically measure the breath flow rate.

By focusing on the thinner line, it becomes evident that it is the proper representation of the subject's breath flow rate during the test, as it captures the essential data needed for accurately assessing the results.