**Core Concept**
Cherry red postmortem staining, also known as "cherry red discoloration," is a phenomenon observed in the retina and other tissues after death. It is caused by the accumulation of oxygenated hemoglobin in the retinal vessels, which gives the retina a characteristic cherry red appearance.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of oxygenated hemoglobin accumulation. In the setting of certain conditions, the blood-brain barrier is disrupted, allowing oxygenated hemoglobin to enter the retina and other tissues. This is particularly seen in cases of carbon monoxide poisoning, diabetic retinopathy, and certain types of traumatic brain injury. The oxygenated hemoglobin binds to myoglobin in the retinal tissues, causing the characteristic cherry red discoloration.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because cherry red postmortem staining is not typically associated with hemorrhagic shock.
**Option B:** This option is incorrect because cherry red postmortem staining is not typically associated with carbon dioxide poisoning.
**Option C:** This option is incorrect because cherry red postmortem staining is not typically associated with anemia.

**Clinical Pearl / High-Yield Fact**
Cherry red postmortem staining should be distinguished from other causes of retinal discoloration, such as subarachnoid hemorrhage, which can cause a pink or grayish discoloration of the retina.

**Correct Answer: C. Anemia.**