Final answer:
The known elements that are considered essential for good health are the essential elements. There are 19 essential elements that are absolutely required in the human diet for survival, and an additional 7 elements are thought to be essential for humans.
Step-by-step explanation:
The known elements that are considered essential for good health are the essential elements. There are 19 essential elements that are absolutely required in the human diet for survival, and an additional 7 elements are thought to be essential for humans. Therefore, the correct answer is A) 10.