Choose the best answer.

What is the definition of life span?
1.the changing of a country to an industrial economy and culture
2.what could be expected or anticipated
3.a substance, or material, made up of tiny particles
4.the time between birth and death
5.the practice of bodily cleanliness

4. the time between birth and death

The best answer for the definition of life span is option 4: the time between birth and death.