The statement "Blood alcohol content is the ratio of alcohol in the system to blood in the system" is indeed true. Blood alcohol content (BAC) is a measure of the amount of alcohol present in a person's bloodstream. Specifically, it is defined as the concentration of alcohol in the blood. It can be expressed in various units, but it is often given as a percentage that indicates the grams of alcohol per 100 milliliters of blood.
So, the correct answer is:
a) True
