**Core Concept**
Blood storage temperature is critical to prevent the degradation of blood components, particularly red blood cells (RBCs), which can lead to hemolysis and reduced efficacy of transfusions. The ideal storage temperature for whole blood and blood components is between 1°C to 6°C, which slows down the metabolic processes and preserves the viability of RBCs.

**Why the Correct Answer is Right**
The correct storage temperature range for blood is between 1°C to 6°C, as it prevents the growth of bacteria and other microorganisms while maintaining the integrity of the blood components. This temperature range also slows down the glycolytic process in RBCs, which helps to preserve their deformability and reduces hemolysis. The use of a refrigerated blood bank storage unit ensures that the blood is stored at a consistent temperature within this range.

**Why Each Wrong Option is Incorrect**
**Option A:** -2 to -4 degrees Celsius is too cold and can cause the blood to freeze, leading to hemolysis and reduced viability of RBCs.
**Option B:** -2 to 0 degrees Celsius is also too cold and may cause the blood to freeze, although to a lesser extent than option A.
**Option D:** 6 to 12 degrees Celsius is too warm and can accelerate the metabolic processes in RBCs, leading to hemolysis and reduced efficacy of transfusions.

**Clinical Pearl / High-Yield Fact**
Blood stored at room temperature or above can cause a significant increase in the pH of the blood, leading to the formation of carbonic acid and potentially life-threatening complications. Therefore, it is essential to ensure that blood is stored at a temperature between 1°C to 6°C to maintain its viability and prevent adverse reactions.

**✓ Correct Answer: C. 1 to 6 degrees Celsius**