Final answer:
The solute from the given list found in higher concentration inside the cell rather than outside is proteins.
Step-by-step explanation:
The question is asking which of the listed solutes is found in higher concentration inside the cell rather than outside of it. Sodium is known to be more concentrated in the extracellular fluid (ECF) than in the intracellular fluid (ICF). Similarly, chloride is the predominant extracellular anion.
Meanwhile, proteins are generally found in higher concentrations within the cell and play numerous roles in cell structure and function, which makes them different from the other listed solutes that are electrolytes primarily concerned with creating osmotic pressure and electrical neutrality. Therefore, the solute found in higher concentration inside the cell rather than outside is proteins (C).