Hello,
I believe you're asking which option is true. If so, A) do not require a medium. Unlike mechanical waves, electromagnetic (or light) waves do not require a medium. It has been proven that light travels in a straight line. Light waves are, in fact, electromagnetic radiation, and they can travel in a vacuum.
Faith xoxo
A theory in science is a remark on what happened
Answer: Mutualism
Explanation: The definition of mutualism states " interaction between two or more species where each species has a benefit". The bird is getting food from the insects and the horse is getting the insects removed. Both are benefited.
The theory was originally developed as island biogeography, to explain species richness of actual islands, principally oceanic. It proposes that the number of species found in an undisturbed insular environment is determined by immigration and extinction.
Explanation:
Wilson of Harvard, developed a theory of "island biogeography" to describe such uneven distributions. They suggested that the number of species on any island displays a balance within the rate at which new species establish it and the rate at which residents of secured species become extinct.
