B. More drastic change than a point mutation
Answer:
The tail of the sperm, the flagellum
Explanation:
We find cilia in the human body. They coat the epithelial cells of the upper respiratory tract and play a role in keeping dust particles, smog, and potentially harmful microorganisms from entering the lungs.
Their movements enable the movement of mucus or other substances across the surface of various epithelial cells. The cilia also cover parts of the male and female reproductive tract.
Flagella are found in sperm, whose tail represents the flagellum in its structure. The body wall of the sponge, among others, contains cells with whips that create and maintain the flow of water through the body.
I believe the correct answer would be B. Semipermeable means that it allows certain substances to pass through, and certain other ones to not pass through. So given all of your options, I would say that B makes the most sense. Hope this helped!
-TTL