Which kind of wave would be observed in outer space between planets, where there is very little matter? a. an electromagnetic wave, such as an x-ray b. an electromagnetic wave, such as a sound wave c. a mechanical wave, such as an x-ray d. a mechanical wave, such as a sound wave

The correct answer is option A) An electromagnetic wave, such as an x-ray.

Explanation-

Sound wave is a mechanical wave, which needs a medium for its propagation. There is no medium between planets that is it is an empty space or vacuum.

Hence, sound wave can not propagate in between planets.

X ray is an electromagnetic wave, which needs no medium for its propagation. It can travel in space with the velocity of light.

Thus, the correct option is A).

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.