Final answer:
The fluid compartment with a high Na and protein concentration is called blood plasma.
Step-by-step explanation:
The fluid compartment with a high Na and protein concentration is called blood plasma (option b).
This is because blood plasma contains high concentrations of sodium, chloride, bicarbonate, and protein. It is one of the two components of the extracellular fluid (ECF), along with interstitial fluid (IF). Both plasma and IF have similar compositions and higher concentrations of sodium, chloride, and bicarbonate compared to the intracellular fluid (ICF), which has elevated amounts of potassium, phosphate, magnesium, and protein.
Therefore, the correct answer is plasma (option b).