Of the Statements That Follow, Which One Describes the Best

Of the statements that follow, which one describes the best way to determine the severity of a patient's blood loss?

A) "I estimate the blood loss based on the fact that one cup of blood is about 250 mL."
B) "If the pulse rate is over 100 beats per minute, the patient has lost at least 200 mL of blood."
C) "I use the patient's signs and symptoms to judge the severity of the blood loss."
D) "I look at the blood pressure, and if it is less than 100 systolic, the patient has lost 500 mL of blood."