Final answer:
The pseudomembrane formation on the tonsils and throat is a classic sign of diphtheria, caused by Corynebacterium diphtheriae. The presence of this pseudomembrane is a diagnostic feature used to identify this serious infectious disease.
Step-by-step explanation:
The development of a pseudomembrane on the tonsils and throat is characteristic of diphtheria. This infectious disease is caused by Corynebacterium diphtheriae, which is a gram-positive rod bacterium. When the bacterium produces the diphtheria toxin, it leads to cell death and an inflammatory response resulting in the formation of a grayish pseudomembrane consisting of dead host cells, pus, red blood cells, fibrin, and infectious bacteria. This pseudomembrane can obstruct airways and lead to serious complications such as suffocation, heart damage (myocarditis), and nerve damage that may impair breathing.
The correct answer to the presented question is Option 5: diphtheria. Diphtheria can be diagnosed based on clinical symptoms like the presence of a pseudomembrane and vaccination history, and confirmed with bacterial cultures from throat swabs and detection of the diphtheria toxin using various techniques including polymerase chain reaction (PCR) and immunological tests.