The answer for your question is C
There are two broad classes of seismic waves: body waves and surface waves. Body waves travel within the body of Earth. They include P, or primary, waves and S, or secondary, waves. P waves cause the ground to compress and expand, that is, to move back and forth, in the direction of travel.
The correct answer is C. Virus.
Virus falls on the gray area which is between nonliving and living things.
Virus is referred to as the small infectious agent which replicates only inside the living cells. Virus can infect life forms plants and animals and microorganisms, for example, archaea and bacteria.
They live in form of independent particles which are referred to as virions. Some viruses can evolve from plasmids.
Within a single water molecule.. H2O.. The hydrogens are bonded to the oxygen covaently.
Between water molecules.. as in a water droplet.. the molecules are held together by hydrogen bonds between them..