**Core Concept**
The buffering action of hemoglobin is a critical aspect of oxygen transport and acid-base balance in the blood. Hemoglobin's ability to buffer hydrogen ions (H+) is essential for maintaining the body's acid-base homeostasis, especially during conditions like respiratory or metabolic acidosis.

**Why the Correct Answer is Right**
The amino acid responsible for the buffering action of hemoglobin is Histidine. Histidine has a pKa value of around 6.0-7.0, which allows it to effectively buffer hydrogen ions at physiological pH. This buffering capacity is crucial for maintaining the stability of the hemoglobin molecule and preventing excessive acidification of the blood. The histidine residue in hemoglobin is located in the globin part of the molecule and plays a key role in its oxygen-binding properties.

**Why Each Wrong Option is Incorrect**
**Option A:** Glutamic acid is not primarily responsible for the buffering action of hemoglobin. While glutamic acid does have a buffering capacity, it is not the primary amino acid involved in hemoglobin's buffering action.
**Option B:** Aspartic acid is another amino acid with buffering properties, but it is not the primary amino acid responsible for hemoglobin's buffering action.
**Option C:** Arginine is a basic amino acid, but it is not directly involved in the buffering action of hemoglobin.

**Clinical Pearl / High-Yield Fact**
Hemoglobin's buffering capacity is crucial for maintaining acid-base balance in the blood. The buffering action of hemoglobin is most effective in the pH range of 6.5-7.5, which is close to the normal physiological pH of the blood.

**Correct Answer:** C.