<prompt> The major sign of hypoventilation is:CyanosisDyspnoeaHypercapniaHypoxia  <response>: In hypoventilation the amount of air moving in and out of lungs is reduced. Hypoventilation results in hypoxia reduced oxygen availability to cells, hypercapnia increased CO2 content of blood, dyspnoea difficulty in breathing and death. Hypercapnia sign stimulates respiratory centre excessively and leads to dyspnoea symptom. 