Which one of the following statements is wrong?

Options

A. Buna-N stands for natural rubber
B. PVC stands for polyvinyl chloride
C. PAN stands for polyacrylonitrile
D. PMMA stands for polymethylmethacrylate

Answer

To determine which statement is wrong among the provided options, we will analyze each statement regarding the polymers mentioned.

### Step 1: Analyze the first statement
The first statement claims that "Bunion stands for natural rubber." We need to verify if this is true or false.

- **Analysis**: Bunion is actually a synthetic rubber, not natural rubber. It is synthesized from the monomers buta-1,3-diene and acrylonitrile. Therefore, this statement is incorrect.

### Step 2: Analyze the second statement
The second statement claims that "polyvinyl chloride stands for PVC."

- **Analysis**: This statement is correct. PVC is indeed the abbreviation for polyvinyl chloride, which is a widely used synthetic plastic polymer.

### Step 3: Analyze the third statement
The third statement claims that "PEN stands for polyacrylamide."

- **Analysis**: This statement is incorrect. PEN actually stands for polyethylene naphthalate, while polyacrylamide is abbreviated as PAM. Thus, this statement is also wrong.

### Step 4: Analyze the fourth statement
The fourth statement claims that "polymethyl methacrylate stands for PMM."

- **Analysis**: This statement is correct. PMM is indeed the abbreviation for polymethyl methacrylate, which is a transparent thermoplastic often used as a lightweight or shatter-resistant alternative to glass.

### Conclusion
Based on the analysis:
- The first statement about Bunion is incorrect as it refers to synthetic rubber.
- The second statement about PVC is correct.
- The third statement about PEN is incorrect.
- The fourth statement about PMM is correct.

Thus, the wrong statements are the first and third ones. However, since the question asks for one wrong statement, we can conclude that the first statement is the most commonly referenced incorrect statement regarding natural rubber.

### Final Answer
The wrong statement is: "Bunion stands for natural rubber."