How many liters of blood can a full-size adult typically hold?

A full-size adult typically holds about 5 to 6 liters of blood, making this the correct answer. Blood volume can vary based on several factors, including body size and composition, but for the average adult, this range is generally accepted in medical and physiological contexts. Understanding blood volume is critical, especially in situations such as trauma or medical emergencies where blood loss can significantly impact a person's health.

The other ranges provided do not accurately reflect the typical volume for adults. For instance, 3-4 liters is insufficient for average adult physiology, while 6-7 liters exceeds the typical physiological limits for most adults. This knowledge is essential for first responders and medical professionals when assessing and managing patients.