What must the test instrument be during the recession of refusal?

The correct answer is that the test instrument must be readily available during the recession of refusal. This means that the instrument should be accessible and operational should the subject decide to take the breath test after initially refusing. The importance of having the instrument readily available is tied to the enforcement and legal processes surrounding DUI laws. Timely access ensures that if the individual changes their mind, law enforcement can comply with relevant regulations and conduct the test without unnecessary delays, which might otherwise compromise the integrity of the evidence.

Having the instrument in the possession of the subject or in the custody of another officer does not adequately guarantee that the test can be administered immediately. Additionally, while recent calibration is important for accurate readings, it is not directly related to the availability of the instrument at the moment of the refusal. The primary focus during the recession of refusal is ensuring that the apparatus is on hand for use, facilitating compliance with legal procedures if the situation changes.