Which of the following options best describes adaptation for survival in organisms?

Adaptation means a feature that an organism is BORN with — it is inherited through its genes — and that helps it survive and produce young in its own habitat. Examples are the thick fur of a polar bear, the deep roots of a desert plant, or the sharp beak of a hawk.

The important idea is the link to survival and reproduction. Individuals with a helpful inherited trait live longer and leave more offspring, so over many generations that trait becomes common in the population. That is natural selection at work.

The other choices describe something else. Changing the environment to suit itself is not adaptation of the organism. Traits an organism picks up during its own lifetime, like bigger muscles from work or a suntan, are acquired characteristics and are not passed on. And new traits do not appear on demand because the environment changed; the variation must already exist through mutation and be selected for.