What does "bottled-in-bond" indicate about a bourbon?

"Bottled-in-bond" signifies that a bourbon is produced under specific government regulations established by the Bottled-in-Bond Act of 1897. This designation ensures that the bourbon meets criteria regarding production practices, which includes that it must be the product of a single distiller at a single distillery during a single distilling season. Additionally, for it to be labeled as bottled-in-bond, it must be aged for at least four years in a new charred oak barrel and bottled at precisely 100 proof (50% alcohol by volume). This designation not only guarantees quality and authenticity but also offers a level of consumer protection, as it holds producers accountable to these standards.

The other options do not accurately capture what bottled-in-bond entails, as they focus on aspects like aging, ingredient sourcing, or proof levels that are not central to the "bottled-in-bond" classification.