]which of these statements is correct about the theory of adaptation?

Adaptations are the result of evolution in different living organisms. This process occurs amazingly through gene mutation but it takes a very long period in time. Adaptation processes occur to help species survive and thrive in the ecological balance of life. Structural adaptations are physical features of an organism that adapted through time. An example of this are the bills of a bird and the fur of bears that they generally need for their survival; birds for hunting, and bears to protect them from low climate areas.

Evolution by adaptation has three results:
Adaptation
By-product
Noise

You didn't provide us with any sentences? The theory of adaptation generally states that when we have organisms over a longer period of time in a certain area, they will continuously adapt to the limitations and challenges found in their environment. For that reason, they will be better and better over time in how they handle their environment. 

This is a time line from 685 to 978