Read the following Assertion and Reason and choose the correct option. Assertion: In severe cases of pneumonia, the lips and fingernails may turn grayish or bluish. Reason: The grayish or bluish discoloration is due to the lack of oxygen resulting from fluid-filled alveoli in the lungs.

Step-by-step solution

Many viruses also cause diseases in human beings. Rhino viruses represent one such group of viruses which cause one of the most infectious human ailments – the common cold. They infect the nose and respiratory passage but not the lungs. The common cold is characterised by nasal congestion and discharge, sore throat, hoarseness, cough, headache, tiredness, etc., which usually last for 3-7 days. Droplets resulting from cough or sneezes of an infected person are either inhaled directly or transmitted through contamina