You are presented with the question "Viral and what disease can both be caused by injury of the lungs" and the following answer choices: 
- tongue
 - the skin
 - bacterial
 - throat
 - Pollution
 - fungi
 - smoking
 - ribs

Now knowing that pneumonia may be caused by an infection or injury of the lungs and viral pneumonia is usually milder than bacterial pneumonia, choose the best answer.


 

   bacterial      