Which of the following vowels is the rounded vowel?

• A./i/ <br/>
• B.<img src="http://timg.fentiku.com/javaimportItems/9fa0434cbd9a4e8bb81fdcc092f9a6fb/images/0.png" /><br/>
• C./a:/ <br/>
• D./i:/ <br/>

正确答案：B