Why do cells divide even after an organism reaches adulthood?

The answer is most definitely the second option or "B". This is because, how you think you grow fingernails, or skin over a wound.

The answer is 2nd option ,full grown organisms need to replace aging and damaged cells

one is through turgidity. this occurs before ground tissue ( collenchyma

and sclerenchyma cells) become well

developed to give structural support to the plant as it grows bigger. the xylem

tissue (composed of rigid tissue) of the young

plant render this support and also maintaining osmotic turgidity of the surrounding

plant cells.