Consider the following statements: Self-sustaining chain reaction is possible in a nuclear reactor, because 1. In each fission reaction relatively number of newtons are released. 2. Newtons take immediate part in fission processes. 3. Fast newtons are slowed down by graphite. 4. Every newton released in the fission process initiates further fission. Which of the above statements are correct?

• A. 1,2 and 3
• B. 1 and 3
• C. 2 and 4
• D. all these