Correct the following statements by changing the underlined part of the sentence.
PAN is prepared from `ul("butadiene")`.

Explanation

To correct the statement, we need to identify the incorrect part and replace it with the appropriate term.

### Step 1: Identify the Incorrect Term
The original statement is: "PAN is prepared from **butadiene**." Here, "butadiene" is incorrect.

### Step 2: Replace with the Correct Term
The correct term to replace "butadiene" is "acrylonitrile." Therefore, the corrected statement is: "PAN is prepared from **acrylonitrile**."

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