## **Core Concept**
The question tests the understanding of the affinity of carbon monoxide (CO) to hemoglobin (Hb) in comparison to oxygen (O2). Hemoglobin is a protein in red blood cells that carries oxygen throughout the body. The affinity of gases to hemoglobin is crucial for understanding various physiological and pathological conditions.

## **Why the Correct Answer is Right**
Carbon monoxide has a significantly higher affinity to hemoglobin compared to oxygen. The affinity of CO to Hb is approximately 210-240 times higher than that of O2. This high affinity results in the formation of carboxyhemoglobin (COHb), which reduces the capacity of blood to carry oxygen. This is a critical concept in understanding carbon monoxide poisoning.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option suggests a lower affinity, which is incorrect given the well-established high affinity of CO for Hb.
- **Option B:** This option implies a similar or slightly higher affinity but does not accurately reflect the significantly higher affinity of CO for Hb compared to O2.
- **Option D:** This option suggests a much higher affinity than correct, which, although closer, does not accurately represent the comparative affinity.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that even low concentrations of CO can lead to significant tissue hypoxia because of its high affinity for Hb. This makes CO poisoning particularly dangerous, as it can occur through exposure to small amounts of CO, such as from faulty heating systems or running a car in an enclosed space.

## **Correct Answer:** . 200-220 times more.