The answer is: B) silkworms.
“While sitting in her garden she deduced the secret of silk by watching the silkworms. She developed the process to remove the thread from the cocoon and set up silk cultivation farms and the weaving of the new cloth.” (Source: http://4kyws.ua.edu/SI_LING_CHI.html)
Natural selection means that the organisms better adapted to their environment, that is, they have developed the right characteristics/skills/response to the external ambient, have higher chance to survive, making the next generations genetically inherit such acquired surviving characteristics.
These generations will thus have a higher chance of survival, making these species being "naturally selected" as survivors, while those who haven't or are slower in this process, have a higher risk of elimination.
Answer:
Gravity?
Explanation:
Or it could be a non contact force.
