**Core Concept**
The question requires the application of the Fick principle to calculate cardiac output. The Fick principle states that cardiac output is equal to the oxygen consumption of the body divided by the difference in oxygen concentration between the pulmonary artery and pulmonary vein.

**Why the Correct Answer is Right**
To calculate cardiac output using the Fick principle, we use the formula: Cardiac Output (CO) = Oxygen Consumption (VO2) / (Pulmonary Artery Oxygen Concentration (CaO2) - Pulmonary Vein Oxygen Concentration (CvO2)). We are given VO2 as 240 ml/min, CaO2 as 160 ml/L, and CvO2 as 180 ml/L. Plugging these values into the formula, we get: CO = 240 / (160 - 180) = 240 / -20 = -12 L/min. However, cardiac output cannot be negative, indicating a miscalculation. The correct calculation should be CO = 240 / (180 - 160) = 240 / 20 = 12 L/min.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided.
**Option B:** This option is not provided.
**Option C:** This option is not provided.
**Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
When using the Fick principle to calculate cardiac output, it is essential to ensure that the units are consistent and that the calculation is performed accurately. A common mistake is to forget to convert units or to miscalculate the difference in oxygen concentrations.

**Correct Answer: C. 12 L/min.**