In Ordinary Circumstances, Which of the Following Describes the Relationship

 In ordinary circumstances, which of the following describes the relationship between sodium and extracellular fluid levels?

A) Sodium levels and extracellular fluid levels are positively correlated.
B) Sodium levels and extracellular fluid levels are negatively correlated.
C) Sodium levels do not correlate systematically with extracellular fluid levels.
D) Sodium levels typically remain low when extracellular fluids are low or normal but increase dramatically when extracellular fluids are high.