Final answer:
An adaptation is an 2. inherited trait that enhances an organism's ability to survive and reproduce, such as thick fur in snow leopards for cold environments.
Step-by-step explanation:
An adaptation is a heritable trait that enhances an organism's ability to survive and reproduce in a particular environment. Among the choices provided, the one that is true of an adaptation is that it is a trait that can be inherited. Adaptations arise over many generations through the process of evolution by natural selection, and once developed, they become part of the organism's genetic makeup. It's important to distinguish that adaptations are different from learned behaviors, which can be acquired within an organism's lifetime, and unlike adaptations, may not be passed on to the next generation.
Examples of adaptations include a snow leopard's thick fur, which is an adaptation for living in cold environments, and the webbed feet of a platypus, which are an adaptation for swimming. Adaptations can change over time as natural selection acts on the genetic variation within a population, allowing organisms to track changes in their environment. However, a true adaptation is a genetic feature that is passed down through generations, not something that can be lost or acquired within a single organism's lifetime.