Answer:
Option B, The amount of water in the blood
Step-by-step explanation:
This can be understood from the scenario as described below –
Suppose the quantity of water (volume by volume, v/v or %) in blood is equal to X litre which constitute Y% of the total blood volume.
Then, the volume of blood can be determined in the following ways-
Y % of blood volume is equal to X liters
Then
litres
Blood Volume
litres
Thus, in this way if amount of water in blood is known, then the blood volume can be determined.