Which of the Following Substances Has the Lowest Renal Clearance $\mathrm{K}^{+}$

Multiple Choice

Which of the following substances has the lowest renal clearance?

A) Creatinine
B) Glucose
C) $\mathrm{K}^{+}$
D) $\mathrm{Na}^{+}$
E) Para-aminohippuric acid (PAH)