The answer that fits the blank provided above is STEROIDS. Steroids are fat-soluble signal molecules. This is one of the derivative compounds of cholesterol along with Vitamin D and bile salts. All steroid hormones are considered as a derivative of cholesterol. The answer for this would be option D.
Answer:
If it´s not A then choose C
Explanation
If they were land animal and could not swim then the only logical reasoning would be that the two pieces of land drifted apart from each other and the fossils were in between them and that´s why they ended up in the ocean.
B. Being new to the country, it is safer for Sarah to take precautions until she gets acclimated
I believe this is the answer as the other answers take too many assumptions as the question doesn't explicitely state that Sarah has skin problems.