Step 1: Read what is being asked.
The answer sits in the last line, so I read it first.
Step 2: Go back to the passage.
The phrase worst abuser appears once, and one country follows it. I match that country to the options.
Step 3: Test the choice "Pakistan" (option 1).
Mentioned in another context, so it is out.
Step 4: Test the choice "China" (option 2).
It is the country attached to the phrase worst abuser, so it is in.
Step 5: Test the choice "Afghanistan" (option 3).
Mentioned in another context, so it is out.
Step 6: Test the choice "North Korea" (option 4).
Not mentioned, so it is out.
Quick recheck.
I read the chosen line of the passage once more and compare it word by word with the correct choice. The other three choices either change the meaning or bring in something the passage does not say.
Final Answer:
Option 2 is stated in the last sentence.
\[ \boxed{\text{Option 2}} \]
