Q. Common cold is not cured by antibiotics because it is :
(a) Not an infectious disease.
(b) Caused by a virus.
(c) Caused by a Gram-positive bacterium.
(d) Caused by a Gram-negative bacterium.
Solution : Correct option: B The common cold is a viral infection of the upper respiratory system, which includes the nose, throat, sinuses, eustachian tubes, trachea, larynx, and bronchial tubes. The most common groups include rhinoviruses and coronaviruses. Antibiotics are useless against a cold, and can only enhance bacterial resistance, if used carelessly.