Final answer:
A chemical test indicating an alcohol concentration of .08 or a detectable amount of a controlled substance typically means the individual is under the influence of alcohol or drugs, respectively. An alcohol concentration of .08 is legally considered intoxication and can significantly impair cognitive and motor functions.
Thus option A. is correct answer.
Step-by-step explanation:
If chemical tests show an alcohol concentration of .08 or any detectable amount of a controlled substance, it generally indicates that the person is under the influence either of alcohol, a controlled substance, or both. Legally, an alcohol concentration of .08 is often the threshold for being consdiered legally intoxicated or under the influence of alcohol.
Acute alcohol administration can lead to alcohol intoxication, characterized by euphoria at lower doses and sedation at higher doses. Cognitive functions such as reaction time and behavioral control are decreased, and at even higher levels, one might experience loss of consciousness.
Moreover, the presence of a detectable amount of a controlled substance indicates that a person has used a drug that is legally restricted due to its potential for abuse or addiction. When combined with alcohol, these substances can produce more pronounced impairment.
Thus option A. is correct answer.