_ Which of the following is not a naturally occurring nuclear fuel?$?

• A. Uranium‚Äö√Ö¬™¬¨‚â§38
• B. Thorium‚Äö√Ö¬™¬¨‚â§33
• C. Plutonium‚Äö√Ö¬™¬¨‚â§39
• D. None of these