What are the only factors in Blood Alcohol Concentration (BAC)?

Blood Alcohol Concentration (BAC) is primarily influenced by the amount of alcohol consumed and the weight of the individual. The more alcohol a person drinks, the higher their BAC will be, and an individual's body weight plays a significant role in how alcohol affects their system. Generally, a lower body weight means a higher BAC for the same amount of alcohol consumed, as there is less body mass for the alcohol to distribute through. This relationship is crucial for understanding alcohol's effects and for assessing impairment.

The type of drink and the time factor are also relevant but secondary. Different beverages have varying alcohol contents, and the duration over which alcohol is consumed can affect BAC as well. However, the fundamental factors for calculating BAC and understanding how it affects a person remain the amount of alcohol ingested and the individual's weight. Hence, the correct answer focuses on these two key elements.