Common cold differs from pneumonia in:

The correct option is D Pneumonia infects alveoli while common cold affects nose and respiratory passage
The common cold is a viral disease, which is caused by a viral infection of the upper respiratory tract (nose and throat), whereas pneumonia is an inflammatory condition of the lung affecting primarily the microscopic air sacs known as alveoli. It is usually caused by infection with viruses or bacteria and, less commonly with other microorganisms. Typical symptoms include cough, chest pain, fever, and difficulty in breathing.
So, the correct answer is 'Pneumonia infects alveoli while common cold affects nose and respiratory passage'.