The correct answer that would best complete the given statement above would be the first option. Coral reefs are built by a small organism called a polyp. The polyp creates the structure of the coral reef by building a CUP out of a calcium carbonate. The skeletons of these tiny corals s<span>ecreted by the lower portion of the polyp. Hope this answer helps.</span>
Alternative energy sources are those that do not deplete natural resources and do not harm the environment.
Options A, B, and C are all fossil fuels, which we know can be depleted and harm the environment.
The only valid option here is D, Geothermal energy.
Geothermal energy is both renewable and environmentally friendly.
According to the theory of evolution, most of Earth's current species developed from distinctly different species which existed earlier in time.
<span>Anything in an organism's environment that causes it to react is called a STIMULUS. A stimulus is defined as an impulse that evokes a specific functional response from an organism. In living organisms, stimulus can occur both internally and externally. Stimulus generate appropriate response in living organisms. Thus, the correct option is C.</span>
