True statement about diptheria toxin is –
**Core Concept**
Diptheria toxin is a potent exotoxin produced by *Corynebacterium diphtheriae*, causing diphtheria. The toxin's mechanism involves inhibiting protein synthesis.
**Why the Correct Answer is Right**
Since the correct answer choice is missing, let's discuss the general mechanism of diphtheria toxin. It works by inactivating the elongation factor EF-2 through ADP-ribosylation, thereby inhibiting protein synthesis. This leads to cell death, particularly in the respiratory tract, causing the disease's characteristic pseudomembrane formation.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option text, we cannot provide a detailed explanation.
**Option B:** Similarly, without the text, we cannot comment on its accuracy.
**Option C:** This option is also unknown.
**Option D:** The same applies to this option.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that diphtheria toxin's effects can be neutralized by antitoxin, making prompt administration crucial in suspected cases.
**Correct Answer:** Unfortunately, the answer choices are not provided.