David is a 75 year old man with COPD. He is drowsy and unwell possibly with a septic condition. His blood gas results are: pH 7.25, pCO₂ 7.1 kPa, pO₂ 10.2 kPa, HCO₃ 28 mmol/L. What is David most likely experiencing?
a. Respiratory alkalosis with renal compensation
b. Metabolic acidosis
c. Respiratory acidosis
d. Respiratory acidosis with renal compensation
