In Virginia, drivers who are under 21 years of age are presumed to be under the influence of alcohol when their blood alcohol content (BAC) is what level?

In Virginia, the legal standard for drivers under 21 years of age is notably stricter than for adult drivers. This demographic is presumed to be under the influence of alcohol with a blood alcohol content (BAC) level of .02 or higher. The rationale behind this low threshold is to discourage underage drinking and driving, as even small amounts of alcohol can impair a young driver's abilities and increase the risk of accidents. Setting the BAC level at .02 reflects a commitment to keeping roadways safe, particularly as younger drivers are typically less experienced and more susceptible to the effects of alcohol.

The other options represent BAC levels that pertain to adult drivers, where the legal limits are higher ('0.08' is the general threshold for most adults, and '1.0' is not a recognized legal limit under any state’s driving laws). Thus, the answer indicates a special rule designed to enhance safety among underage individuals.