Which of the following is a non-fissile material?$?

• A. Plutonium‚Äö√Ö¬™¬¨‚â§39
• B. Uranium‚Äö√Ö¬™¬¨‚â§35
• C. Uranium‚Äö√Ö¬™¬¨‚â§33
• D. Thorium‚Äö√Ö¬™¬¨‚â§32