A Patient Has the Following Laboratory Values: - Arterial $\mathrm { pH } = 7.55$

A patient has the following laboratory values: - Arterial $\mathrm { pH } = 7.55$
- Plasma $\mathrm { HCO } _ { 3 } { } ^ { - } = 40 \mathrm { mEq } / \mathrm { L }$
- Plasma chloride concentration $= 101 \mathrm { mE } \mathrm { q } / \mathrm { L }$
- Arterial $\mathrm { pCO } _ { 2 } = 48 \mathrm {~mm} \mathrm { Hg }$
- Plasma sodium $= 150 \mathrm { mEq } / \mathrm { L }$ What is the most likely cause for his abnormal acid-base status?

A) Abnormal lung function (e.g., pneumonia)
B) Excessive aldosterone secretion
C) Impaired renal tubular HCO3^- reabsorption
D) Chronic renal failure
E) Diarrhea