**Core Concept**
The central chemoreceptor's sensitivity to changes in carbon dioxide levels is crucial in regulating breathing. In patients with Chronic Obstructive Pulmonary Disease (COPD), the body's ability to sense and respond to CO2 levels is altered due to chronic hypoxia and hypercapnia.

**Why the Correct Answer is Right**
The central chemoreceptor is sensitive to the pH of the cerebrospinal fluid (CSF), which is directly related to the CO2 levels. In COPD patients, chronic hypoxia leads to an increase in CO2 levels, causing a decrease in CSF pH. This decrease in pH activates the central chemoreceptor, leading to an increase in breathing rate to compensate for the increased CO2 levels. The sensitivity of the central chemoreceptor is increased in COPD patients due to chronic hypercapnia, allowing them to detect even slight changes in CO2 levels.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the sensitivity of the central chemoreceptor is not decreased in COPD patients. While the peripheral chemoreceptors may be less sensitive, the central chemoreceptors are more sensitive in response to chronic hypercapnia.
* **Option B:** This option is incorrect because the central chemoreceptor's sensitivity is not directly related to the peripheral chemoreceptors. While both play a role in regulating breathing, they are separate mechanisms.
* **Option C:** This option is incorrect because the central chemoreceptor's sensitivity is not increased due to chronic hypoxia alone. It is the combination of chronic hypoxia and hypercapnia that leads to an increase in sensitivity.

**Clinical Pearl / High-Yield Fact**
In COPD patients, the central chemoreceptor's increased sensitivity to CO2 levels can lead to respiratory alkalosis during episodes of acute hypercapnia, such as during an asthma exacerbation.

**Correct Answer: D.**