At low CO₂ concentration, oxygen dissociation curve of haemoglobin will

• A)

  shift to right

• B)

  shift to left

• C)

  become irregular

• D)

  become vertically straight

Whenever there is high need of oxygen in the body the curve shift to right creating low O₂ affinity which means when CO₂ is high in body we need oxygen so therefore the curve shifts to right to release more oxygen.
In case there is less CO₂ this means there is high amount of oxygen in the body so the curve shifts to left which causes high oxygen affinity for haemoglobin meaning that, haemoglobin does not release oxygen easily.
Therefore the answer is option (b).