To be eligible for an Indiana driver's license, you must be at least _____ old.

Answer: B — 16 years old and 180 days

In Indiana, the minimum age requirement to obtain a driver's license is 16 years old and 180 days. This means that a person must not only turn 16 but also need to have held a learner's permit for at least 180 days, which allows them to gain essential driving experience under supervision before being eligible for a full license. This graduated approach to licensing is designed to ensure that young drivers develop their skills gradually, thereby increasing safety on the roads. The other age options reflect different stages or requirements of the licensing process in Indiana. For instance, individuals can apply for a learner's permit at 15 years old, but they cannot receive a full driver's license until they meet the 16 years and 180 days requirement. The options of 17 and 18 years old indicate ages at which individuals may also become eligible for a full license, but those ages exceed the minimum necessary requirement and do not represent the specific eligibility criteria set by the state.