Longer than your mom on bed
Inkjet printer, I believe.
Stem cells are undifferentiated cells that could develop to perform a variety of tasks. One type of stem cell is the embrionic stem cell. There are also adult stem cells. To use embrionic stem cell you need to have fertilized embrios. These can be donated to research. The use of the embrionic stem cells is controversial for this reason.
Short answer:
It has a "birth" (in the nebula) just like humans are born inside their mothers.
It gets older and changes(in color which is due to its Temperature and in Size) just like humans as they go from babies to adults to elders. They also both die (Stars exploded or become black holes) stars "die out" and humans literally die. Both can die(not literally for stars) from old age.
The answer is A) prepares organisms for future changes in the environment
