In the pulmonary capillaries, formation of oxyhaemoglobin is favoured by

• A

  High ${\mathrm{pO}}_2$, low ${\mathrm{pCO}}_2$, low  pH and low temperature

• B

  Low ${\mathrm{pO}}_2$, high ${\mathrm{pCO}}_2$, low  pH and high temperature

• C

  High ${\mathrm{pO}}_2$, low ${\mathrm{pCO}}_2$, low ${\mathrm{H}}^{+}$ concentration and high temperature

• D

  High ${\mathrm{pO}}_2$, low ${\mathrm{pCO}}_2$, low ${\mathrm{H}}^{+}$ concentration and low temperature