The most serious and potentially fatal type of pericarditis among the options provided is:
**c. Suppurative**
Suppurative (purulent) pericarditis is characterized by the presence of pus in the pericardial space, often due to bacterial infection. This condition can lead to severe complications, such as cardiac tamponade, and can be life-threatening if not treated promptly.
While tuberculous pericarditis can also be serious, suppurative