With reference to the latest developments in columnar cell research, consider the following statements: 1. Embryo is the only source of human stem cells at the cystic stage. 2. Columnar cells can be obtained without destroying the corpuscles. 3. Column cells can literally survive on their own for eternity. 4. Indian research centers also created some cell lines which can be grown in many types of tissues. Which of the above statements are correct?

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