**Blood alcohol concentration (BAC)** is the amount of alcohol present in the blood after drinking. This amount does not reach its peak immediately after drinking; it takes some time to do so. According to the information provided, the moment when the BAC is highest is approximately **one hour after consuming alcohol**. This means that the maximum level of alcohol in the blood is reached between **30 and 90 minutes** after drinking.

This time can vary depending on several factors, such as the type of drink, the amount of alcohol consumed, the person's weight and gender, among others. For example, alcohol reaches the blood faster if consumed with certain drinks like tonic or soft drinks. Additionally, the body processes alcohol differently depending on the speed at which it is drunk and whether or not food has been consumed beforehand.

Therefore, the statement that BAC reaches its peak between 30 and 90 minutes after drinking is correct, as it reflects the time necessary for the alcohol to be fully distributed in the body and reach its maximum concentration in the blood.