Q. With reference to the latest developmentsin stem cell research, consider the following statemets:1. The only source of human stem cells are the embryos at blastocyst stage.2. The stem cells can be derived without causing destruction to blastocysts.3. The stem cells can regenerate themselves in vitro virtually forever.4. Indain research centres also created a few cell lines which can be developed into many types of tissues.Which of these statements are correct ? 

1. 1,2,3 and 4
2. 1,2 and 3
3. 1,2 and 4
4. 3 and 4