Why Is Stewart's Strong Ion Approach to Acid-Base Balance Not

Why is Stewart's strong ion approach to acid-base balance not used clinically instead of the Henderson-Hasselbalch equation?

A) Clinically, it is unwieldy and overly complex.
B) Its conceptualization of the role of HCO₃^- is inaccurate.
C) It is so close conceptually that there is no need to change.
D) Theoretically, it is inferior to the H-H equation.