Final answer:
Naturally occurring elements consist of 90 elements on Earth.
Step-by-step explanation:
The number of elements that occur naturally is 90 (Option C).
An element is a substance composed of atoms that have the same number of protons in their atomic nucleus. Naturally occurring elements are those that can be found on Earth without being synthesized in a laboratory. Examples of naturally occurring elements include hydrogen, oxygen, carbon, and gold.
These elements can be found in various forms in the Earth's crust, atmosphere, oceans, and living organisms.
Learn more about Naturally occurring elements