If you are driving and are 21 years old or older, you are considered to be driving under the influence when your blood alcohol concentration (BAC) is a minimum of:
- 0.02 percent.
- 0.04 percent.
- 0.06 percent.
- 0.08 percent. ✓
Answer: D. 0.08 percent.
For a driver 21 or older, the minimum blood alcohol concentration for driving under the influence is 0.08 percent.
Why this is the answer
The handbook's DUI section says you can be charged with Driving Under the Influence when you are driving or in physical control of a vehicle while under the influence of alcohol or drugs, and it ties a breath or blood alcohol level of .08 or above to an administrative license suspension at arrest. The .08 figure in that passage is the level the state treats as unlawful, which is why the answer is 0.08 percent rather than a lower number.
Why the other answers are wrong
- A. 0.02 percent. — Nothing in the handbook passage gives 0.02 percent as the level for an adult driver; the figure it states for an unlawful alcohol level is .08.
- B. 0.04 percent. — 0.04 percent is not the number the handbook uses for an adult driver's alcohol level; the passage names .08.
- C. 0.06 percent. — 0.06 percent is below the level the handbook states, so it does not match the rule described in the passage.
Remember it
Remember the pair: adult driver, point-zero-eight — the same number the officer's test has to reach before the license is suspended at arrest.