**Core Concept**
The underlying principle being tested is the understanding of acid-base balance, specifically the relationship between pCO2, bicarbonate levels, and the diagnosis of respiratory acidosis with metabolic compensation.

**Why the Correct Answer is Right**
Given the high pCO2 level (80 mm Hg), which indicates respiratory acidosis due to hypoventilation, and the elevated plasma bicarbonate level (33 mEq/L), it suggests a compensatory mechanism. The body tries to compensate for the acidosis by increasing bicarbonate reabsorption in the kidneys, thus the high bicarbonate level.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not account for the compensatory increase in bicarbonate.
**Option B:** This option is incorrect as it suggests a different acid-base disorder.
**Option C:** This option is incorrect because it does not match the given laboratory values.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that in respiratory acidosis, the kidneys will try to compensate by increasing bicarbonate reabsorption, and the expected increase in bicarbonate can be estimated.

**Correct Answer:** D. Respiratory acidosis with metabolic compensation.