Which of the following exercises is NOT part of the standard exercises in the SFST?

The Breathalyzer Test is the correct answer because it is not considered one of the standard field sobriety tests used in the SFST protocol. Instead, the Breathalyzer is a separate tool used for measuring the blood alcohol concentration (BAC) level in a person's breath, which assists officers in determining if a driver is over the legal BAC limit.

In contrast, the Horizontal Gaze Nystagmus, Walk-and-Turn, and One-Leg Stand are specifically designed to evaluate a person's physical coordination, balance, and cognitive processing abilities, which can be impaired by alcohol consumption. These exercises are integral to the SFST protocol and are scientifically validated to assess whether a driver is likely impaired. The tests are administered in a standardized manner to ensure reliability and consistency, which is essential for accurate field assessments of impairment.