What are the specific clues evaluated in the HGN test?

The correct answer focuses on the key components that are specifically evaluated during the Horizontal Gaze Nystagmus (HGN) test. In conducting this test, officers look for three main clues to determine potential impairment from alcohol or other substances:

1. Lack of smooth pursuit: This refers to the inability of the eyes to move smoothly when following a target, indicating potential impairment.

2. Distinct and sustained nystagmus at maximum deviation: If nystagmus is observed when the eyes are at their maximum lateral position for an extended period, it suggests significant impairment.

3. Onset of nystagmus prior to 45 degrees: The presence of nystagmus before the eyes reach an angle of 45 degrees is a critical indicator of intoxication.

These three aspects provide evidence of how a subject's ability to track a moving object is affected by the influence of alcohol, making them essential components of the HGN test. The other options include varying criteria that do not align with the standardized measures used in the HGN assessment or include unrelated symptoms, further confirming the accuracy of the selected choice.