Identify the conditions given below at the time when oxy-haemoglobin dissociation curve turns to the left.
a. Blood supplying O₂ to tissues
b. A fall in pCO₂ and rise in pH
c. Haemoglobin bound with O₂ on the lung surface
d. A rise in pCO₂ and fall in PH

A shift to the left indicates increased hemoglobin affinity for oxygen and an increased reluctance to release oxygen. Several physiologic factors are responsible for shifting the curve left or right, such as pH, carbon dioxide (CO₂), temperature, and 2,3-Disphosphoglycerate.

The curve shift to the left when pO₂ is high, PCO₂ is low, temperature is low, pH is high and low 2,3-DPG.